New Zealand Thecate Hydroids Part IV.—The Family Plumulariidae

Transactions of the Royal Society of New Zealand : Zoology, Volume 1, Issue 3, 14 July 1961, Page 19

New Zealand Thecate Hydroids Part IV.—The Family Plumulariidae

Patricia M. Ralph

By

Abstract

Records 10 genera and 34 species of New Zealand plumularian hydroids; Plumularia (12 species); Halopteris (4 species); Nemertesia (3 species); Antennella (2 species), and one species each of Pycnotheca, Halicornopsis and Monoserius; Thecocarpus (4 species; Aglaophenia (4 species) and Halicornaria (2 species); describes keys, and discusses the systematic status of the New Zealand species of this family resulting in the following changes; Antennella serrata Totton, 1930 recognized as Antennella africana Broch, 1914; three species of Aglaophenia (previously regarded as unidentifiable) now determined —Aglophenia huttoni (Goughtrey, 1876) as Halicornopsis elegans (Lamarck, 1816); Aglaophenia huttoni Kirchenpauer, 1872 as Halicornaria longirostris (Kirchenpauer, 1872) and Aglaophenia incisa (Goughtrey, 1876) as Thecocarpus incisus (Goughtrey); Aglaophenia filicula Hilgendorf, 1897 remains as indeterminable; Thecocarpus rostratus (Bale, 1924) is a synonym of Thecocarpus incisus (Goughtrey); Thecocarpus ctenatus Totton, 1930 is Aglaophenia ctenata (Totton); Hemicarpus banksii (Gray, 1843) is Monoserius hanksii (Grey); Plumularia wilsoni Bale, 1924 and Nemertesia cymodocea (Busk, 1851) are new records from New Zealand. One new species of Thecocarpus is described.

Introduction

The Plumulariidae with 34 species are the second largest family of New Zealand thecate hydroids. The unilateral arrangement of the hydrothecae borne on regular pinnately arranged lateral offshoots (hydrocladia) of the erect main stem or directly from the hydrorhiza, the fusion of the hydrotheca for some, or all of its adcauline length, the lack of a permanent operculum in the hydrotheca and the presence in all species of the family of nematothecae, give the members of this family a distinctive appearance.

A great deal of what has already been said of the distribution, number of endemic species, etc., of the New Zealand sertularians can also be said of the plumularians. Nearly all the plumulanan species from our waters are either restricted to the New Zealand area (16 species) or to the Southern Hemisphere (15 species). Of the remaining three species one is known from a few low latitude Northern Hemisphere localities, another is best known from several low and higher latitude localities in the North Atlantic Ocean and the last, Plumularia setacea Ellis is cosmopolitan.

Eight of the sixteen endemic species are rare, having been taken only once in our waters. Four of these are species of Plumularia, the other four are species of Halopteris, Halicornaria, Monoserius and Thecocarpus. All the rare endemic species with

the exception of that of Monoserius and Thecocarpus were dredged by the “ Terra Nova ” in the far north of New Zealand from the area surrounding Cape Maria van Diemen, North Gape, and the Three Kings Islands. The recorded locality of the rare species of Monoserius is “ New Zealand ” and that of Thecocarpus is from off the Chatham Islands.

Plumularians are found in our waters from the intertidal region down to 380 fathoms, and vary in size from those with tiny stems 0.30 cm in length and in which the hydrocladium has only one thecate internode, to tall branched stems, up to 60.0 cm in length, and with many hydrothecae per hydrocladium.

The plumularians in the present collection referred to in this paper have been taken all round the New Zealand coast, but more especially from latitudes south of Auckland, including Stewart Island and the Chatham Islands. Measurements of size, slide number and figures given for the species are derived from the author’s personal collection of thecate hydroids unless othewise stated. This collection is lodged with the Zoology Department, Victoria University of Wellington. Where species have many synonyms, only an abbreviated list is given, but a reference source for fuller synonymy is included.

Acknowledgments

The author wishes to thank Professor L. R. Richardson for his continued encouragement and helpful advice; the Governors of the “ Musgrave Fund”, Cambridge University, England, for financial assistance which greatly facilitated field collection; The Nuffield Foundation, London; Dr. W. J. Rees, and Mr. E. White, of the British Museum (Natural History), special thanks for assistance and allowing the author to examine hydroid material while holding a Nuffield Travelling Fellowship at the Natural History Museum; Dr. C. W. Brazenor, National Museum, Melbourne, for the loan of specimens; Dr. P. L. Kramp, Universitets Museum, Copenhagen, and Dr. F. S. Russell, Marine Biological Station, Plymouth, England, and Dr. Maurice Blackburn, University of Hawaii, for literature; the library staff of this University, and Miss M. Wood, Secretary of the Royal Society of New Zealand, for helpful cooperation in obtaining literature; the Directors of the Dominion Museum, Wellington, the Auckland Institute and Museum, the Canterbury Museum, Christchurch, and the Otago Museum, Dunedin, for loan of their hydroid collections; Miss Pamela Pennycuik, University of Brisbane, Australia, Dr. Elizabeth J. Batham, Marine Biological Station, Portobello, Dunedin; Professor G. Knox, Mrs. K. Kiddle, and Mrs. S. Rind, Canterbury University, Christchurch, Mr. R. Kulka and Mr. C. Trevarthen, Auckland University, Auckland, Mr. W. H. Dawbin, Sydney University, Australia, and Mr. J. Garrick, Victoria University, Wellington, and to many other friends who from time to time have given valuable help in collecting material.

Family PLUMULARIIDAE L. Agassiz, 1862

Hydrothecae on one side only of the lateral shoots (hydrocladia); with rare exceptions lacking a permanent operculum; adnate for some, or all of the adcauline length; margin of hydrotheca with teeth, or lacking teeth entirely; nematothecae always present either on stem or hydrocladia or both: gonosome either simple, and unprotected by accessory structures or with accessory protective structures; sometimes showing sexual differentiation; reproductive zooid producing a fixed sporosac.

Key to the Subfamilies and Genera of the Family Plumulariidae in New Zealand

1. (12) Length of fixed adcauline wall of hydrotheca short in relation to the length of the internode, rarely (Fig. the internode, frequently less than 7, a) more than half the length of

half (Fig. 1, j) hydrotheca, with few exceptions (Fig. 7, c) with an entire smooth margin; nematothecae with few exceptions (Fig. 5, f), bithalamic (Fig. 1, a and j), free, and moveable Subfamily Plumulariinae Kuhn, 1913

2. (9) Lateral nematothecae, alongside or above hydrotheca almost always present; hydrotheca without an abcauline intrathecal ridge (“shelf”) separating the true hydrothecal cavity from a secondary external theca.

3. (4) Stems simple, hydrocladium arising directly from the hydrorhiza and forming the erect stem Antennella Allman, 1877

4. (3) Hydrocladia (pinnae) arising from an erect stem and/or branches.

5. (8) Hydrocladia in one plane and on two sides of stem and/or branches.

6. (7) Hydrothecae present on hydrocladia only; hydrocladia simple (not regularly bifurcated) Plumularia Lamarck, 1816

7. (6) Hydrothecae present on stem and hydrocladia; hydrocladia simple Halopteris Allman, 1877

8. (5) Hydrocladia arranged in two or more series, or in whorls, not in the same plane Nemertesia Lamouroux, 1816

9. (2) Lateral nematothecae absent; hydrotheca with an abcauline intrathecal ridge separating the true hydrothecal cavity from a secondary external theca.

10. (11) Abcauline wall of secondary theca not perforated by diverticulae Pycnotheca Stechow, 1919

11. (10) Abcauline wall of secondary theca containing three diverticula from the true hydrothecal cavity Halicornopsis Bale, 1882

12. (1) Length of fixed adcauline wall of hydrotheca long, in relation to the length of the internode, usually more than half the length of the internode (Fig. 10, a); hydrothecae with few exceptions possessing an undulated or toothed margin; nematothecae, monothalamic, tubuliform, fixed, not moveable Subfamily Aglaopheniinae Stechow, 1911

13. (14) Gonosome surrounded by simple gonotheca, unprotected by accessory structures; hydrotheca usually with variable number of small spinous processes round the hydropore (Fig. 7, f) nematothecae frequently pear-shaped (Fig. 7, i) Halicornaria Busk, 1852

14. (13) Gonosome protected by secondary hydrocladia (Fig. 10, e)

15. (16) Secondary hydrocladia modified, arranged in one row, on one side of the primary hydrocladium Monoserius Marktanner-Turneretscher 1890

16. (15) Secondary hydrocladia not arranged in one row, but into a corbula

17. (18) Secondary hydrocladium I with hydrotheca at base (Fig. 10, f) Thecocarpus Nutting, 1900

18. (17) Secondary hydrocladium I without hydrothecae at base (Fig. 10, g) ...... Aglaophenia Lamouroux, 1816

The characters recognized in keying out the genera of the Subfamily Plumulariinae are as follows:—For Nemertesia [ (as Antennularia ) Nutting, 1900] for Antennella and Plumularia (Bedot, 1921) and for Pycnotheca, Halicornopsis and Halopteris (Totton, 1930) : For the present the genera Pycnotheca and Halicornopsis are included within the Plumulariinae and not in Stechow’s (1921) Subfamily Kirchenpaueriinae, and the genera of the Subfamily Aglaopheniinae (based on the characters of the gonosome) as defined by Leloup (1932 a), except that the genus Thecocarpus as keyed above, is recognized as possessing the combined characters of Leloup’s genera Bithecocarpus and Trithecocarpus. Two genera only, in the Subfamily Aglaopheniinae—namely, Halicornaria and Nematocarpus (not known from New Zealand) have the gonosome unprotected by accessory structures. The short glossary below (after Pennycuik, 1959) is given as a guide to the terminology in current usage for the gonosome accessory structures which in general are modified hydrocladia and often called “ phylactocarps

(1) Primary hydrocladia (Fig. 10, f (1) ); ( gonocladia of Totton (1930) ) ; modified hydrocladia belonging to the same series as the unmodified hydrocladia of the rest of the stem. They may, or may not, bear secondary hydrocladia. (2) Secondary hydrocladia I (Fig. 10, f (2) ); (= cretes basales of Billard (1913); gonohydrocladia of Totton). Hydrocladia, often much modified, springing from the primary hydrocladia. This series found only in association with the gonosome.

(3) Secondary hydrocladia II (Fig. 10, f (3) ); (r= costae); the third order of modified hydrocladia forming the ribs of the corbulae of Thecocarpus and Aglaophenia. Each arises from a secondary hydrocladium I. (4) Secondary hydrocladium 111 (Fig. 10, f (4) ) ( costal apophysis) ; the fourth order of modified hydrocladia arising from secondary hydrocladia II and found only in certain species of Thecocarpus.

In the absence of the gonosome, two features of the erect stem are fairly reliable in distinguishing species of the genus Halicornaria. Most species of this genus, including both those already known from New Zealand, have tiny needle-like chitinous processes bordering the hydropore (Fig. 7, f) and pear-shaped (Fig. 7, i) rather than tubuliform lateral nematothecae flanking the hydrotheca. As yet no reliable erect stem characters have been found to distinguish Aglaophenia, Thecocarpus and Monoserius.

Antennella Allman, 1877

Erect stem simple, representing the hydrocladium of other plumularians and divided, apart from the basal region, into alternating athecate and thecate internodes ,• occasionally a few irregularly placed lateral shoots similar in structure to the stem are found; hydrotheca with lateral nematothecae; nematothecae not attached to hydrotheca.

Only A. ritchiei Totton, 1930 and A. africana Broch, 1914 are known from New Zealand. Through the kindness of Dr. N. Millard, specimens of A. africana from South Africa have been examined resulting in the identification of A. serrata Totton, 1930 with A. africana Broch. Both Totton (1930) and Millard (1957) forsaw the possibility of A. serrata being a synonym of A. africana.

Material of A. ritchiei and A. africana is meagre in the present collection, approximately 50 stems of the former from one locality and some 20 stems of the latter from three localities. A. ritchiei is a New Zealand species and A. africana is also known from South Africa.

Key to the Species of Antennella in New Zealand

1. (2) A well marked oblique node below the first two hydrothecae otherwise nodes not readily observed; internodes between hydrothecal internodes, with two mesial nematothecae; hydrotheca projecting well out from the internode, with flared margin but nearly cylindrical when

viewed laterally; lateral pair of nematothecae arising from apophysis of internode and usually extending beyond the margin of the hydrotheca ...... A. ritchiei Totton, 1930

2. (1) All proximal nodes defining the hydro thecal internodes well marked and very oblique but distal nodes, transverse and often poorly developed athecate internodes between hydro thecal internodes with one (occasionally two) mesial nematothecae; hydrothecae with abcauline and adcauline sides parallel; lateral pair of nematothecae arising from internode apophysis but not extending beyond the margin of the hydrotheca A. africana Broch, 1914

Antennella ritchiei Totton, 1930 Fig. 1, d-e and h.

1930. Antennella ritchiei Totton, p. 211, text-fig. 52, a-b.

Erect stems thin hair-like hydrocladia, up to 1.0 cm in length, and arising from stem-like bundles of hydrorhizal tubes; hydrorhizal tubes with scattered bithalamic nematothecae; basal hydrocladial region athecate, up to 2.75 mm in length and divided by transverse nodes into internodes of irregular length; distal athecate internode with two or three, more or less evenly spaced nematothecae, other athecate internodes usually without nematothecae; a well developed oblique node between the last basal athecate internode and the remainder of the hydrocladium which is divided alternately into thecate and athecate internodes by alternating transverse and oblique nodes; distal node of thecate internode transverse, that of the athecate internode steeply oblique, both transverse and oblique nodes often not readily observed; thecate internodes 0.40 to 0.45 mm in length; athecate internodes 0.30 to 0.52 mm in length; hydrocladium 0.13 to 0.15 mm in width measured at the base of the hydrotheca; hydro thecae large, close together, but projecting well out from the internode; margin flared; hydrotheca slightly compressed dorso-laterally, nearly cylindrical when viewed from the side; free adcauline wall considerably shorter than the aperture diameter; floor of hydrotheca with a sharp upward curve on the adcauline side; abcauline wall 0.21 to 0.25 mm in length; length of the free adcauline wall 0.08 to 0.10 mm, length of fixed adcauline wall 0.06 to 0.08 mm; diameter at margin of hydrotheca 0.22—0.25 x 0.23-0.28 mm; nematothecae bithalamic, somewhat scoop-shaped with adcauline side shorter than abcauline; nematothecae from 0.045 to 0.075 mm in length; 0.02 to 0.045 mm in width at the aperture; two mesial nematothecae on the athecate internodes of the medial and distal regions of the hydrocladium; five nematothecae on each thecate internode, one mesial subhydrothecal nematotheca, and two pairs of nematothecae lateral to the hydrotheca and, of these lateral pairs, one pair large, each nematotheca carried on a well developed apophysis and reaching almost to the margin of the hydrotheca and, a much smaller pair, the members of the pair arising from the base of the apophysis of the larger pair: gonothecae arising from the hydrocladium singly between the base of the hydrotheca and the subhydrothecal nematotheca; female gonotheca broad, carried on a pedicel of two segments; distal end truncated; distal terminal aperture subcircular; two nematothecae on sides of lower part of gonotheca; length of young female gonotheca excluding the pedicel 0.35 to 0.45 mm and maximum diameter 0.20 to 0.30 mm.

Locality. Type locality, off Three Kings, New Zealand, 300 fathoms (Totton, 1930): off Moeraki, 40 fathoms (P.M.R.), 11/2/51, 57.

There are five stem-like bundles of hydrorhizal tubes of A. rite hie in the present collection, the shortest 1.0 cm in length, three others approximately 2.0 cm and one 3.0 cm, the latter carrying 38 hydrocladia. The hydrocladial nodes are better developed in these specimens than in those described by Totton (1930) from the far North, off Three Kings Islands. Only one fertile hydrocladium was found bearing four young female gonothecae which are very similar in form and size to those of A. africana.

Antennella africana Broch, 1914. Fig. 1, a-c, f-g, and k.

1914. Antennella quadriaurita Ritchie forma africana Broch, p. 26. 1923 a. Antennella africana Broch. Stechow, p. 13 (synonymy). 1925. Antennella africana Broch, Stechow, p. 492, fig. 41. 1930. Antennella serrata Totton, p. 212, text-fig. 53. 1932. Antennella quadriaurita Ritchie. Leloup, p. 162, pi. XVI, fig. 2 (synonymy). 1957. Antennella africana Broch. Millard, p. 226.

Erect stems, thin, hair-like hydrocladia up to 1.5 cm in height and arising in clusters from intertwining hydrorhizal tubes; hydrorhizal tubes usually with numerous scattered, narrow, funnel-shaped nematothecae; basal hydrocladial region divided by transverse nodes into up to five athecate internodes of irregular length; basal athecate region 1.0 to 2.0 mm in length; longer internodes with two or three nematothecae but last athecate internode may have as many as six; shorter athecate internodes lacking nematothecae; a well developed oblique node between the last basal athecate internode and the remainder of the hydrocladium, which is divided alternately into thecate and athecate internodes by alternating transverse and oblique nodes; distal node of thecate internode transverse, that of the athecate internode steeply oblique; oblique nodes well developed, transverse nodes often not readily recognizable; internodes of variable length, usually the athecate internodes the longer in the medial region of the hydrocladium but shorter than the thecate internodes in the distal region; athecate internodes 0.23 to 0.58 mm in length; thecate internodes 0.33 to 0.48 mm in length; hydrocladium 0.10 to 0.125 mm in width measured at the base of the hydrotheca; hydrotheca large, and deep with the adcauline and abcauline sides approximately parallel; free adcauline wall approximately the same length or less than the aperture diameter; floor of hydrotheca with a sharp upward curve on the adcauline side so that it is almost at right angles to the long axis of the hydrocladium; abcauline wall 0.19 to 0.27 mm in length; length of free adcauline wall approximately 0.15 mm, length of fixed adcauline wall approximately 0.10 mm; diameter at margin of hydrotheca 0.16 to 0.26 mm; hydrocladial nematothecae, bithalamic, somewhat scoopshaped with adcauline side shorter than the abcauline; nematothecae from 0.09 to 0.10 mm in length; 0.04 to 0.05 mm in width at the aperture; usually one mesial nematotheca, sometimes two, on each athecate internode; five nematothecae on each thecate internode, one mesial subhydrothecal nematotheca and two pairs lateral to the hydrotheca and of these latter pairs, one pair large each nematothecae of the pair borne on a well developed apophysis but nematothecae not reaching the margin of the hydrotheca, and a much smaller pair, the members of the pair arising from the base of the apophysis of the larger nematothecae: gonothecae arising from the hydrocladium in ones or twos, between the base of the hydrotheca and the subhydrothecal nematotheca; both male and female may be present on one hydrocladium or on separate hydrocladia; when on the same hydrocladium the male gonothecae are distal and the female proximal in position; male gonotheca carried on a pedicel of one segment, elongate, tapering gradually proximally and distally; distal terminal aperture subcircular, closed by a deep-convex operculum; one nematotheca on side of the lower part of the gonotheca; length of male gonotheca excluding the pedicel, 0.31 to 0.54 and maximum diameter 0.13 to 0.23 mm; female gonotheca carried on a pedicel with two segments, larger than the male, broader, truncated at the distal end; distal terminal aperture subcircular, with shallow-convex operculum; two nematothecae on sides of lower part of gonotheca; length of female gonotheca excluding the pedicel, 0.68 to 0.77 mm and maximum diameter, 0.38 to 0.47 mm.

Locality. Type locality, West Africa (Broch, 1914): off Three Kings Island Stn. 90 “Terra Nova”, 100 fathoms (Totton, 1930); off Cape Maria van Diemen, Stn. 144, “Terra Nova”, 35-40 fathoms (Totton, 1930); Doubtless Bay on submarine cable, 10 fathoms (P. & T. Dept.), 14/8/51, 209; Tamaki Strait, Auckland, approx. 40 fathoms (G. Trevarthen). 26/5/50, 739; off Moeraki, 40 fathoms (P.M.R.), 11/2/51, 65.

Distribution. Indian Ocean; Gough Island, South Atlantic; French Congo; S.W. Africa; Havana; South Africa; New Zealand.

Totton in 1930 considered that the “ close approximation of the hydrothecae ” adequately distinguished the New Zealand species A. sen at a from A. africana Broch. More information is now available on the characteristics of the latter species and specimens kindly sent me by Dr. Millard show the hydrotheca as close together, or closer, than those observed by Totton in A. sen at a and as other stem and hydrothecal characters are similar in the two species, A. sen at a is recognized here as a synonym of A. africana Broch.

Plumularia Lamarck, 1815

Erect stem athecate, carrying branches and/or hydrocladia on an apophysis of the stem; a transverse node between the stem apophysis and the branch and/or hydrocladium; hydrocladia either on two sides and in one plane, or, spirally arranged on stem and branches; hydrocladia simple, not regularly bifurcated; hydrotheca usually with a pair of suprathecal lateral nematothecae.

In New Zealand as elsewhere (Fraser, 1946) the genus Plumularia has the greatest number of recorded species in the family Plumulariidae. Twelve species are described here, and of these, eleven have been previously recorded from our waters.

The new record for New Zealand is Plumularia wilsoni Bale, 1926 (= P. delicatula Bale, 1882), a small species best known from the intertidal zone and first described from Victorian waters in Australia. Its known distribution in both Australia and New Zealand is sporadic. P. spinulosa Bale, 1882, and P. pulchella Bale, 1882 are known from Australia and South Africa and are very probably circumpolar in distribution. P, hyalina Bale, 1882, P. wattsi Bale, 1887, P. setaceoides Bale, 1882 and P. wilsoni Bale, 1926, are known also from Australia, while P. hrachiata Totton, 1930, P. tenuissima Totton, 1930, P. triangulata Totton, 1930, P, diploptera Totton, 1930 and P, spirocladia Totton, 1930, are endemic species and rare, P. setacea (Ellis, 1755) is cosmopolitan. Of the twelve species above, half of them, namely P. hyalina, P. pulchella, P. wilsoni, P. setacea, P. spinulosa and P. wattsi are best known from the intertidal zone and the remaining six species from the sublittoral zone down to 300 fathoms.

The species of Plumularia in our waters can be readily recognized and grouped on the habit of the erect stem. First, there are those species in which the hydrocladia have only one short athecate internode and one longer thecate internode. To this group belong P. spinulosa, P. pulchella and P. hyalina. These species also have short stems rarely more than 2.0 cm in height. Then, there are those species with a simple monosiphonic stem with alternating hydrocladia and with two, and usually more than two hydrothecate internodes per hydrocladium. To this group belong P. setae ea, P. setaceoides,.P . wilsoni, P. diploptera and P. triangulata. These species are usually taller than those in the first group and have stems up to 8.0 cm in height. Two species have the hydrocladia arranged spirally. Of these, P. spirocladia has the hydrocladia arranged so that in every two ascending turns there are five hydrocladia, while P. wattsi is unique among the New Zealand species of Plumularia in having the hydrocladia not only arranged in irregular spirals, but in having the latter arising from athecate branch internodes (Fig. 1, i), not from the stem. The two remaining species of P. hrachiata and P. tenuissima, have thick, polysiphonic, erect stems and branches.

Key to the Species of Plumularia in New Zealand

1. (17) Hydrocladia constantly with two, or more than two hydrothecae.

2. (22) Nematothecae all bithalamic.

3. (4) Stem carrying long athecate branches (Fig. 1, i) arranged in an irregular spiral from the base to the tip of the stem; hydrocladia also in an irregular spiral, arising from the branches and divided by oblique nodes into short athecate and longer thecate internodes - P. wattsi Bale, 1887

4. (3) Hydrocladia not arising from long athecate branches but directly from the stem.

5. (6) Medial and distal hydrocladia spirally arranged so that in every two ascending turns there are five hydrocladia, the base of the sixth being in line with the first hydrocladium of the spiral; proximal hydrocladia alternate P. spirocladia Totton, 1980

6. (5) Hydrocladia not spirally arranged; hydrocladia either alternate along the whole length of the stem, or, at least in some region of it; where hydrocladia not alternate, subopposite and decussate.

7.(14) Stem monosiphonic; simple or sparingly and irregularly branched.

8. (11) Hydrotheca free from the internode for some of its adcauline length; paired nematothecae generally not reaching the margin of the hydrotheca; aperture oblique, sloping steeply away from the internode.

9. (10) Hydrotheca campanulate; adcauline side straight viewed laterally and frequently much and evenly thickened (Fig. 2, b); a thick wedge-shaped support between the free portion of the adcauline wall and the internode; stem internodes with from one to four septal ridges P. setaceoides Bale, 1882

10. (9) Hydrotheca more or less the same width throughout; abcauline side distinctly bulbous at the base and wall thickened in the submarginal region only (Fig. 2, a); stem internodes occasionally with septal ridges, and the latter usually less than four in number P. wilsoni Bale, 1926 (= P. delicatula Bale, 1882)

11. (8) Hydrotheca not free for part of its length; aperture at approximately 90° to the long axis of the internode.

12. (13) Two nematothecae flanking the axil of the hydrocladium; thecate internodes of hydrocladia with two subthecal septal ridges; stem apophysis with small but distinct “ mamelon ” (Fig. 2, f) on the upper surface; stem nodes transverse not readily distinguished in the medial and distal regions P. diploptera Totton, 1930

13. (12) One nematotheca in the axil of the hydrocladium; thecate internodes of the hydrocladia with one subthecal septal ridge; stem apophysis with barely perceptible “ mamelon ”; stem internodes generally readily recognizable throughout, and usually with a proximal and distal septal ridge P. setacea (Ellis, 1755)

14. (7) Stem and branches polysiphonic; secondary tubules generally run along the sides of the stem and branches that are without hydrocladia.

15. (16) Nodes of the stem transverse and readily observed but irregular in arrangement so that the internodes carry from one to four stem apophyses; lateral suprathecal nematothecae almost reaching the end of the internode P. brachiata Totton, 1930

16. (15) Stem lacking nodes; hydrocladia clearly alternate at end of stem and branches, but elsewhere tend to be subopposite and decussate; lateral suprathecal nematothecae distant from the end of the internode . P. tenuissima Totton, 1930

17. (1) Hydrocladium typically with one hydro theca only, but a few hydrocladia may possess two.

18. (19) Hydro theca with well developed intrathecal shelf: spine on end of hydrocladium well developed, reaching above margin of hydrotheca P. spinulosa var. spinulosa Bale,

1882 19. (18) Hydrotheca without intrathecal shelf.

20. (21) Axil of the hydrocladium with two nematothecae; stem internodes swollen at the distal extremity and often with walls wrinkled internally P. pulchella Bale, 1882

21. (20) Axil of hydrocladium lacking nematothecae; stem internodes not swollen at the distal extremity, and with from one to four thick transverse septal ridges P. hyalina Bale, 1882

22. (2) Nematothecae all monothalamic: stem simple or sparingly branched, monosiphonic, with alternate hydrocladia P. triangulata Totton, 1930

Plumularia wattsi Bale, 1887. Fig. 1, i-j.

1887. Plumularia wattsi Bale, p. 95 1924. Plumularia wattsi Bale, p. 254, fig. 12.

A tall plumularian up to 30.0 cm in height with monosiphonic erect stem carrying long athecate branches arranged in an irregular spiral from the base to the top of the stem: hydro-

branches; branches borne on an apophysis of the stem, and hydrocladia on an apophysis of cladia also arranged in an irregular spiral, arising from the branches and divided by oblique nodes into short athecate and longer thecate internodes; hydrorhiza flattened, strap-like, approximately 0.275 mm in width; basal one or two stem internodes annulated and without the branch; first long internode of the hydrocladia often arising directly from the branch apophysis without an intermediate short internode; stem apophysis 0.25 to 0.40 mm in length; branch apophysis approximately 0.07 mm in length; nodes transverse and of regular occurrence; stem internodes from 0.61 to 1.50 mm in length and internodes of varying length may be present, and irregularly arranged on a single stem; stem internodes 0.175 to 0.30 mm in width; internodes of branches approximately 0.45 mm in length and 0.15 to 0.175 mm in width; long internodes of hydrocladia 0.40 mm to 0.43 mm in length; short internodes 0.11 to 0.175 mm in length; branches approximately 0.07 mm in width; a proximal and distal bandlike thickening on the outer side of each short and long hydrocladial internode; hydrotheca campanulate, with smooth entire margin; aperture at 90° to the long axis of the internode; abcauline length of hydrotheca approximately 0.10 mm; fixed adcauline length 0.06 mm; free adcauline length 0.041; width of hydrotheca at aperture approximately 0.10 mm; nematotheca, bithalamic, canaliculate, wine glass-shaped; four or five nematothecae on each stem internode carrying a branch, one on each side of the base of the branch converging towards each other in the axil and two or three more or less evenly spaced and in line on the internode; a pair of nematothecae also at the base of the hydrocladia; a mesial nematotheca below the hydrotheca on the long internode and two laterally placed above the hydrotheca; a mesial nematotheca on each short internode; length of nematotheca 0.095 mm approximately; and width at aperture of cup approximately 0.021 mm; gonotheca (female), elongate oval produced distally into a long narrow neck and carried on a short stalk at the base of a secondary branch; length of gonotheca approximately 0.80 mm and 0.30 to 0.35 mm in maximum width; stalk approximately 0.10 mm; distal terminal aperture 0.055 mm approximately.

Locality. Type locality, Port Phillip, Victoria, Australia (Bale, 1887): Napier foreshore, on storm drifted sea-weed, (P.M.R.) 19/10/50, 8; Port Chalmers (c.f. Bale, 1924), Canterbury Museum Slide No. 49; Portobello Marine Biological Station, wooden test block A. 283 (D. Hurley), 723; Channel between Portobello M.B.S. and Quarantine Island, approx. 2 fathoms (P.M.R.) 30/11/51, 260. Distribution. Australia, New Zealand.

This plumularian of distinctive appearance is not well known either from Australian (Port Phillip) or New Zealand (Port Chalmers and Napier) waters. The storm-drift Napier specimens are similar in habit, and the size range of their internodes, hydrothecae, etc., to those growing in several localities in the Port Chalmers area. The New Zealand specimens from the latter area are not fully grown and shorter than those recorded by Bale from Port Phillip.

Plumularia spirocladia Totton, 1930. Fig. 2, f-g.

1930. Plumularia spirocladia Totton, p. 224, text-fig. 60.

A plumularian of medium height with stem up to 5.5 cm in length, simple, monosiphonic, with the hydrocladia carried on a stem apophysis at the distal end of the internode; sometimes two hydrocladia to an internode; hydrocladia at base of stem alternate, but spirally arranged in the medial and distal regions so that in every two ascending turns there are five hydrocladia, the base of the sixth hydrocladium being in line with the first hydrocladium of the spiral; apophysis with small “ mamelon ” in the centre of the upper surface; apophysis 0.12 mm in length; nodes of stem transverse; stem internodes approximately 0.57 mm in length and 0.175 to 0.28 mm in width; nodes of the hydrocladia slightly oblique and dividing each hydrocladium into short athecate and longer thecate internodes; two short internodes between stem apophysis and the first thecate internode; length of short internode 0.10 to 0.27 mm; length of long internodes 0.32 to 0.52 mm; width of hydrocladia 0.05 to 0.10 mm; proximal region of hydrothecate internode swollen; a proximal and distal septal ridge on the short internodes and in addition to these on the longer internodes a subhydrothecal ridge; hydrothecae campanulate, margin entire, smooth, but not level, dipping down to meet the wall of the hydrocladium; abcauline length of hydrotheca approximately 0.10 mm; width at the margin, viewed laterally, approximately 0.11 mm, and at the base of the hydrotheca approximately 0.06 mm; nematothecae bithalamic, conical 0.067 to 0.070 in length and 0.032 to 0.035 mm in width measured at the margin; a single nematotheca on each stem internode about one third of the distance from the base and facing the hydrocladium; a pair of lateral nematothecae at the base of each hydrocladium, flanking the axil; a single nematotheca on each short athecate internode and a single subhydrothecal nematotheca and two nematothecae, one on either side above the hydrotheca reaching nearly the end of the thecate internode: gonotheca, arising from the side

of the stem apophysis, elongate, oval, tapering distally into a narrow neck, proximally into a short stalk; female gonotheca 1.24 to 1.40 mm in length, and 0.32 to 0.37 mm in maximum width; aperture 0.10 to 0.11 mm in width; male gonotheca slightly smaller than female, 0.98 to 1.20 mm in length and 0.30 in greatest width; aperture 0.05 mm in width.

Locality. Type locality, near North Cape, New Zealand, 11—20 fathoms (Totton, 1930). Species known only from the type locality. There is no specimen of this species in the present collection, and the figures are drawn from the British Museum (Natural History) material kindly shown me by Dr. W. J. Rees.

Plumularia setaceoides Bale, 1882. Fig. 2, b-e

1882. Plumularia setaceoides Bale.

1884. Plumularia setaceoides Bale. Bale, p. 136, pi. XI, fig. 8; pi. XIX, fig. 36. 1928. Plumularia setaceoides Bale. Trebilock, p. 24.

1950. Plumularia setaceoides Bale. Hodgson, p. 44, fig. 74.

A medium sized plumularian with monosiphonic stem up to 8.0 cm in height, with recurved, regularly alternate hydrocladia arising from the distal end of the internode, and a hydrorhiza in which the internal wall is undulated; hydrorhiza flattened, stap-like approximately 0.14 mm in width; basal two or three stem internodes without hydrocladia; basal two or three nodes transverse, and internodes in this region often with transverse annulations; nodes elsewhere on stem and hydrocladia oblique, and regular in occurrence; stem internodes from 0.30 to 0.40 mm in length and 0.11 to 0.13 mm in width; stem internodes with from one to four transverse septa; stem apophysis approximately 0.03 mm in length; nodes divide the branches into short athecate internodes and long thecate internodes; hydrocladia with from two to six hydrothecae; short internodes of hydrocladia 0.08 to 0.12 mm in length; width of hydrocladia internodes 0.11 to 0.12 mm; length of long thecate internodes 0.30 to 0.35; hydrotheca deeply campanulate, aperture, more or less circular, with a smooth, entire margin set at an angle of approximately 40° to the long axis of the branch; abcauline wall frequently much thicker than either the lateral or adcauline wall; base of hydrotheca rounded but viewed laterally with a triangular thickening on the adcauline side and a similarly shaped thickening between the proximal free adcauline wall and the branch; length of abcauline side of hydro theca 0.12 to 0.13 mm; length of adcauline side free 0.07 to 0.09 mm; length of adcauline side fixed to hydrocladial internode 0.045 to 0.06 mm; maximum width of hydrotheca 0.11 to 0.13 mm; nematothecae shaped like a wine glass, bithalamic, canaliculate, with slender base and shallow cup; mesial nematothecae on both long and short internodes have a notched margin on the adcauline side; maximum length of nematotheca approximately 0.055 mm and width of aperture of terminal cup approximately 0.025 mm; one nematotheca below each hydrotheca, and one at each side above it not reaching the rim of the hydro theca; one mesial nematotheca on each short internode, one in the axil of each hydrocladium, and one near the proximal end of each stem internode: gonotheca—female gonotheca large, more or less cylindrical; walls almost smooth to transversely rugose; stem short; distal end truncated, often obliquely truncated; length of female gonotheca 1.30 to 1.50 mm; maximum width, approximately 0.50 mm; maximum width across truncated distal end approximately 0.40 mm; length of stalk approximately 0.10 mm; male gonotheca small, about a third the length of the female; ovate, and carried on a readily recognizable narrow stalk; length of male gonotheca 0.375 to 0.45 mm; maximum width 0.20 to 0.275 mm; male and female gonothecae usually arising at the base of a hydrocladium.

Locality. Type locality, Williamstown, Victoria, Australia (Bale, 1882): Long Beach, Russell, Bay of Islands (P.M.R.), 27/11/50, 28; Muriwai Beach, North Auckland, on stormdrifted seaweed (P.M.R.), -/2/53, 320; Narrow Neck, Auckland (G. Trevarthen), 6/5/50, 724; Breaker Bay, Cook Strait, storm-drifted seaweed (V. Gassie), 4/5/52, 294; Makara Beach, west coast, Wellington area, storm-drifted seaweed (V. Gassie), 25/8/52, 302; Moa Point, Lyall Bay, Wellington, on Cystophora retroflexa (M. Curran), 9/10/56, 510; Island Bay, Cook Strait (Trebilcock, 1928); Clarence River mouth, Kaikoura, storm-drifted seaweed (P.M.R.) 13/11/51, 115; Taylor’s Mistake, Christchurch (G. Knox), -/10/56, 233; Menzies Bay, Christchurch (G. Knox), 9/5/51, 720; Portobello Marine Biological Station, reef (P.M.R.), 30/11/51, 264; St. Clair, Dunedin, and Bluff (Trebilcock, 1928); Stn. 49, Port Hutt, L.T. rock pool (Chatham Expedition, 1954), 8/2/54, Chatham Expedition, Slide No. 20.

Distribution. Australia, New Zealand.

Trebilcock (1928) thought it extremely doubtful that P. wilsoni Bale was specifically distinct from P. setaceoides and Vervoort (1946) stated that it was difficult

to distinguish P. setaceoides from P. setacea (Ellis) in the absence of gonothecae. Specimens of all these species from more than one locality are in the present collection and specimens of P. wilsoni and P. setaceoides from Australian waters have been examined through the courtesy of Dr. C. W. Brazenor, of the National Museum, Melbourne, Australia. There seems only one conclusion to be drawn from all this material, and this is that P. setaceoides and P. wilsoni are specifically distinct and readily distinguishable from F. setacea and each other, even in the absence of gonothecae.

In all the material examined four major features at once distinguished P. setaceoides (Fig. 2, b-d) from P. setacea (Fig. 4, a-c). These characters are first, the steep slope of the margin of the hydrotheca away from the internode; secondly, the considerable length of adcauline wall free from the internode so that the hydrotheca stands well out from the former structure; thirdly, the wedge-shaped thickening visible in lateral view between the free adcauline wall and the internode, and fourthly, the pair of nematothecae flanking the hydrotheca are short and do not reach the margin of the cup.

Trebilcock (1928) had difficulty in deciding whether some of his material of Plumularia from Island Bay, Cook Strait, was P. setaceoides or P. wilsoni. The thickness of the hydrothecal abcauline wall is variable in the specimens of P. setaceoides examined, as is also the number and thickness of the septal ridges on the stem and the hydrocladial internodes. The majority of the present New Zealand specimens of P. setaceoides have short, thick stems, with from two to three well developed septal ridges on the stem intemodes and a thick abcauline hydrothecal wall very similar to Bale’s specimens from Queenscliff, Victoria. One group of stems in the present collection, however, from the area of the Portobello Marine Biological Station, Otago, had taller, thinner stems, one or two poorly developed stem septal ridges and a thin abcauline wall to the hydrotheca similar to Bale’s specimens from Williamstown, Victoria. Nonetheless, whatever the thickness of the hydrothecal wall, etc., in P. setaceoides, two features of the hydrotheca are constant in all Bale’s material examined and in the present collection, and these features distinguish P. setaceoides readily from P. wilsoni. First, the angle at which the hydrotheca is placed in relation to the intemode, and secondly, the ratio of the length to the breadth of the hydrotheca. In P. setaceoides (Fig. 2, b and c) the length of the abcauline wall would lie either along, or within a straight line drawn from ihe outer wall at the base of the intemode to the margin of the abcauline wall, while in P. wilsoni (Fig. 2, a) the length of the abcauline wall would lie outside such a line. The length to breadth ratio of the hydrotheca of P. setaceoides is approximately 1:1, while that of P. wilsoni is approximately 1.75:1.

P. setaceoides is equally as well known from New Zealand coastal waters as the cosmopolitan P. setacea and distributed over a very similar latitudinal range—namely, from approximately 36° S. to 46° S. latitude.

Plumularia wilsoni Bale, 1926. Figs. 2, a and h; 3, a-c.

1882. Plumularia delicatula Bale, p. 40, pi. XV, fig. 2. Not P. delicatula Busk, 1852; or P. delicatula Quelch, 1885.

1884. Plumularia delicatula Bale. Bale, p. 137, pi. XI, fig. 5. 1926. Plumularia wilsoni Bale, p. 21 (synonymy).

A small plumularian with monosiphonic stem up to 12.0 mm in height; hydrorhiza with internal pegs or rings or perisarc; hydrorhiza approximately 0.13 mm in diameter; a few tubular nematothecae on the hydrorhiza; first hydrocladium arising from erect stem approximately 0.30 mm above the hydrorhiza; hydrocladia regularly alternate, from 1.0 to 2.0 mm in length and with from three to four hydro thecae; hydrocladia not close together, approximately 0.40 mm apart; nodes readily recognizable oblique constrictions; nodes divide the stem into internodes of approximately equal length, but the hydrocladia into long and short internodes; hydrothecae present only on the long internodes of the hydrocladium and carried at the distal end of the internode; stem internodes 0.40 mm to 0.50 mm in length; stem internodes in the distal region approximately 0.08 mm in maximum width, in the

proximal region approximately 0.12 mm; stem internodes with a proximal and distal annulation and a nematotheca above the distal annulation on the opposite side to the hydrocladium; long internodes of the hydrocladium 0.40 to 0.50 mm in length; short internodes approximately 0.10 mm in length; two nematothecae in the axil of each hydrocladium; hydrothecae carried on the basal third of the long stem internodes, more or less parallel to the long axis of the hydrocladium; both adcauline and abcauline sides of the hydrotheca rounded at the base but contracted below the steeply oblique smooth margin; abcauline wall thickened just below the rim, which has a slight outward flare; one third of the adcauline wall free from the hydrocladium; length of abcauline wall 0.15 to 0.175 mm; length of adcauline wall fixed to the hydrocladium approximately 0.13 to 0.15 mm; length of adcauline wall free from hydrocladium 0.05 to 0.07 mm; maximum width of hydrotheca 0.15 to 0.17 mm; nematothecae bithalamic, cananiculate, slender at the base, terminal cup wide and shallow; maximum length of nematotheca 0.06 to 0.07 mm, and width at aperture of terminal cup approximately 0.035 mm; one nematotheca below each hydrotheca and one at each side above it not reaching the rim of the hydrotheca; one nematotheca on each short internode between the hydrothecae; gonothecae, immature (?) elongate oval approximately 0.30 mm in length with short stem and 0.10 mm in maximum width. Locality. Type locality, Griffiths Point, Victoria, Australia. (Bale, 1882): Island Bay, Cook Strait, on Paramithrax (?) peronii (J. Yaldwyn), 2/10/54, 439; Island Bay, Cook Strait, on Cystophora sp. (D. J. Griffin), -Z9/59, 722; Half Moon Bay, Stewart Island, drift (Mrs. Willa), 10/9/56, 501.

Distribution. Australia, New Zealand.

This species is not well known or widely distributed in New Zealand waters, but appears to be well established in the Island Bay area of Cook Strait. The status of P. wilsoni is discussed above under P. setaceoides. One or two of the basal stem internodes of Bale’s specimen from Griffiths Point have small structures that seem to be small (? male) gonothecae (Fig. 3, c). All the stems in the present collection are infertile.

Plumularia diploptera Totton, 1930. Fig. 3, f-j

1930. Plumularia diploptera Totton, p. 222, text-fig. 59, a-b.

A medium sized plumularian up to 5.0 cm in height, with monosiphonic erect stem; hydrorhiza 0.20 to 0.30 mm in width; basal one or two stem internodes annulated and without a hydrocladium; nodes transverse, or veiy slightly oblique on the hydrocladia; only proximal stem nodes readily recognizable; stem internodes from 0.35 to 0.60 mm in length and 0.15 to 0.30 mm in diameter; stem apophysis 0.08 to 0.22 mm in length and with a small “ mamelon ” on the upper surface about half-way along the length of the apophysis; apophysis usually with a distal sub-terminal thickened annulation; hydrocladia regularly alternate arising very close to the distal end of the stem internode and divided into short, athecate internodes and long, thecate internodes; a short internode separates the first thecate internode from the stem apophysis and has a septal ridge of perisarc about the middle; other short intemodes have a proximal and distal ridge; short internodes 0.17 to 0.29 mm in length; long internodes have a proximal and a distal septal ridge and also a thickening between the proximal ridge and the base of the hydrotheca, and another at the level of the floor of the hydrotheca; long internodes 0.37 to 0.55 mm in length; hydrocladia 0.11 to 0.15 mm in diameter measured at the base of the hydrotheca; hydrothecae small, campanulate with a smooth entire margin and borne about half-way along the internode; abcauline length 0.08 mm to 0.10 mm; width at the margin 0.10 to 0.11 mm and width at the base 0.05 to 0.061 mm; nematothecae bithalamic, canaliculate, with upper cup about half the lower tapering region in depth; stem internode with a single lateral nematotheca on the side opposite the apophysis and about half-way up the internode; a nematotheca at each side of the base of the branch flanking the axil; a single mesial nematotheca on each short internode except that between the stem apophysis and the first thecate internode; a single nematothecae below each hydrotheca and one on each side above it extending well beyond the margin but not reaching the termination of the internode; nematotheca 0.055 to 0.078 mm in length and 0.029 to 0.032 mm in greatest width; gonotheca, elongate oval tapering distally into a long narrow neck with terminal aperture and proximally into a short stalk, gonotheca arising from the axil of a hydrocladium; female gonotheca 1.12 to 1.35 mm in length and 0.20 to 0.39 mm in greatest width; diameter at terminal aperture 0.08 to 0.10 mm; male gonotheca smaller than female 0.58 to 0.96 mm in length, and 0.15 to 0.25 mm in maximum width; diameter at terminal aperture 0.05 to 0.06 mm.

Locality. Type locality, off North Cape, New Zealand Stn. 134 “Terra Nova” 11-20 fathoms (Totton, 1930); off Cape Maria van Diemen, Stn. 144 “Terra Nova” 35-40

fathon „ (Totton, 1930); Motuihi-Motutapu, Auckland, approx. 40 fathoms (C. Trevarthen) 21/8/49, 725; Hadfield Bay, Auckland, storm drift (P.M.R.) 10/2/53, 360; between Port Waikato and Manakau Heads, Auckland (H. J. Chapman) -/—/—, 636; Stn. 20 off Ponui Island, Hauraki Gulf, 10-15 fathoms, “Northern Prawn Expedition” (V.U.W., Zoo. Dept.), 29/8/56, 576; Opunake Beach, Bay of Plenty, drift (P.M.R.), -/2/53, 312; Kahu Rocks, Cook Strait, 20-30 fathoms (F. Abernethy) 18/10/56, 515; Stn. 77, off Palliser Bay, Cook Strait, 435 fathoms (V.U.W., Zoo. Dept.), 23/12/56, 570; Menzies Bay, Christchurch (G. Knox) 9/5/51, 718; Half Moon Bay, Stewart Island, under rocks (G. Knox) 7/1/51, 234; Stn. 18, off Cape Pattison, 15 fathoms (“Chatham Expedition, 1954”) 28/1/54, Chatham Expedition Slide No. 21. This species is known only from New Zealand waters.

Totton (1930) regards P. diploptera as “closely allied to” P. setacea (Ellis) and at the end of his description of P. diploptera notes that the status of the latter species is dependent on further information on four morphological structures of P. setacea. There is sufficient material of both P. setacea and P. diploptera in the present collection to give further information on the morphology of P. setacea and a decision on the status of P. diploptera. P. diploptera as now understood from New Zealand waters is a good species and can be readily identified.

(1) In P. diploptera the hydrocladia are more or less laterally placed and opposite: in P. setacea in New Zealand the hydrocladia always “come off” from one side of the stem (the front), not on opposite sides.

(2) In P. diploptera, basal septal ridges are rarely present on the proximal stem intemodes, which in many instances are the only stem intemodes that are easily observed; in P. setacea there may, or may not be a septal ridge at the base of the stem internodes; the larger stemmed New Zealand variety of this species, however (var. opima ) seems always to possess basal and distal septal ridges.

(3) In P. diploptera a subhydrothecal septal ridge is a constant feature of each intemode: in P. setacea a subhydrothecal ridge is of very rare occurrence but may occasionally be seen on a few hydrocladial internodes in the variety opima. The subhydrothecal ridge when present in this variety, is not restricted to any one region of the hydrocladium, or to the hydrocladia of any one part of the stem.

(4) In P. diploptera there are two clearly observed lateral nematothecae flanking the axil of each hydrocladium: in P. setacea there is only one lateral nematotheca flanking the axil.

P. diploptera and P. setacea have a very similar latitudinal distribution in New Zealand from approximately 34° S. to 47° S. and are known in many instances from the same localities within this range. Both species are known from the intertidal region in New Zealand and P. setacea is best known from this region, but P. diploptera is better known from the sublittoral zone.

Plumularia setacea var. setacea (Ellis, 1755). Figs. 3, e; 4 a, c, and d.

1755. Corallina setacea Ellis, p. 19 pi. 11, N. 16 a; A; pi. 38, fig. 4. 1816. Plumularia setacea (Ellis). Lamarck, p. 129. 1896. Plumularia setacea (Ellis). Farquhar, p. 466 (N.Z. synonymy). 1900. Plumularia setacea (Ellis). Nutting, p. 56, pi. 1, figs. I—4 (synonymy). 1924. Plumularia setacea (Ellis). Bale, p. 252, fig. 11a (synonymy). 1928. Plumularia setacea (Linnaeus). Trebilcock, p. 24. 1937. Plumularia setacea (Linnaeus). Fraser, p. 191, pi. 44, fig. 231, a-c. 1946. Plumularia setacea (Linnaeus). Vervoort, p. 323, fig. 6. 1959. Plumularia setacea (Linnaeus). Pennycuik, p. 180.

A small to medium sized plumularian up to 5.0 cm in height but more usually from 2.0 to 3.0 cm, with monosiphonic stem; basal one or two stem internodes annulated and without hydrocladium; stem nodes transverse or slightly oblique, readily observed in all regions; stem internodes with or without a proximal and distal septal ridge and from 0.31 to 0.45 mm in length and 0.11 to 0.175 mm in width; stem apophyses 0.09 to 0.11 mm in length and (?) with a very small “mamelon” on the upper surface; apophysis with a distal subterminal thickened annulation; hydrocladia regularly alternate arising very close to the distal end of the stem internode and from one side of the stem, divided into short, athecate internodes and, longer thecate internodes; a short internode separates the first

thecate iuternode from the stem apophysis and has a septal ridge about the middle; other short internodes have a proximal and distal ridge; short internodes 0.10 to 0.15 mm in length; long internodes also have a proximal and a distal septal ridge and very rarely a subhydrothecal ridge; long internodes 0.30 to 0.375 mm in length; hydrocladia 0.10 to 0.11 mm in width measured at the base of the hydrotheca; hydrotheca small, campanulate, with a smooth entire margin and borne about half-way along the internode; abcauline wall 0.10 to 0.11 mm in length; width at the margin viewed laterally 0.10 to 0.11 mm, and width at the base 0.05 to 0.06 mm; nematothecae bithalamic, canaliculate, with upper cup about half the depth of the lower tapering region; stem internode with a single lateral nematotheca on the side opposite the apophysis and about a third of the way up the internode; a single lateral nematotheca in the axillary region of the hydrocladium; a single median nematotheca on each short internode except between the stem apophysis and the first thecate internode; a single median nematotheca below each hydrotheca and one each side above it extending well beyond the margin but not reaching the termination of the internode; nematothecae 0.055 to 0.075 mm in length and 0.019 to 0.035 mm in width at the aperture: gonotheca, elongate oval tapering distally into a long narrow neck with terminal aperture and proximally into a short stalk; gonotheca arising from the axil of the hydrocladium; female gonotheca 1.10 to 1.13 mm in length and 0.25 to 0.45 mm in greatest width; diameter at terminal aperture 0.05 to 0.10 mm; male gonotheca smaller than female 0.80 to 0.90 mm in length and approximately 0.25 mm in width; diameter of terminal aperture 0.05 to 0.06 mm.

Locality. Type locality, Brighthelmstone, England (Ellis, 1755): Muriwai Beach, North Auckland, storm drift (P.M.R.), -/2/53, 321; Rangitoto Island, Auckland (G. Trevarthen), 6/6/50, 712; Tauranga (Allman, 1885 as P. multinoda) ; Point Jerningham, Wellington Harbour (P.M.R.), 14/8/50, 728; Island Bay, Cook Strait, on Paramithrax (?) peronii (J. Yaldwyn) 2/10/54, 731; Island Bay, Cook Strait (Trebilcock, 1928); Menzies Bay, Christchurch (S. Rind), 26/8/51, 198; Diamond Harbour, Lyttelton Harbour (E. W. Bennett), 25/1/24, 134; Lyttelton Harbour (c.f. Bale, 1924), Canterbury Slide Nos. 50, 50A, SOB; Sumner (Hartlaub, 1901); Timaru (Hilgendorf, 1898); off Moeraki, 40 fathoms (P.M.R.), 11/2/51, 727; off Karitane, Otago, 10 fathoms, Trawler “Grace” (Hanson Bros.), 30/11/51, 711; Reef, Portobello Marine Biological Station (P.M.R.), 14/2/51, 56; St. Clair, Dunedin (Trebilcock, 1928); Woodpecker Bay, West Coast, South Island (G. Knox), 3/1/52, 390; Port Hutt, Stn. 49, intertidal (“Chatham Exped. 1954”) 8/2/54, Chatham Exped. Slide. No. 22.

Distribution. Essentially cosmopolitan.

In view of the difficulty that has been experienced in the past in distinguishing some material of P. setaceoides and P. diploptera from P. setacea and because there is a varietal form of the latter species described from our waters, a full description is given here of this well known cosmopolitan species. The status of P. setaceoides and P. diploptera and the characters that distinguish these species from P. setacea are discussed above following their description.

In 1889 Bale described as new, P. turgida, from material collected by von Lendenfeld, at Lyttelton, New Zealand. Later, in 1924, Bale recognized his species as P. setacea and also regarded other material from Sumner, a locality close to Lyttelton, as “ corresponding exactly with that which I formerly described as P. turgida and, ... as of somewhat larger proportions throughout than typical forms ” of P. setacea.

Bale’s material from Sumner has been re-examined, and in common with other New Zealand specimens of P. setacea was found to have only one nematotheca in the axil of the hydrocladium. The material collected by von Lendenfeld, however, from Lyttelton, was said to possess two axial nematothecae (Bale, 1889, p. 780). Therefore, von Lendenfeld’s material which Bale recognized as P. setacea is not regarded here as that species. Possibly von Lendenfeld’s material is P. diplotera, a species known to possess two nematothecae flanking the axil of the hydrocladium and a stem rather similar in habit to that of P. setacea. There are specimens in the present collection from Lyttelton, of P. diploptera.

All the robust stems of P. setacea in New Zealand come from the Lyttelton/Banks Peninsula area. The size range and locality of this material is given in the following paragraph. For the present, the specimens are not recognised as a distinct variety of P. setacea.

Stems up to 5.0 cm in length; stem intemodes 0.35 mm in length and 0.20 mm in width; apophysis 0.10 to 0.13 mm in length; short athecate internodes 0.06 to 0.175 mm in length; longer thecate internodes 0.25 to 0.35 mm in length; hydrocladium 0.12 to 0.14 mm in width measured at the base of the hydrotheca; abcauline length of the hydrotheca 0.11 mm; width of hydrotheca at the margin 0.12 to 0.13 and at the base 0.06 to 0.07 mm; nematothecae 0.07 mm in length and 0.03 mm in width at the aperture: gonotheca (female) 1.0 to 1.13 mm in length and 0.30 to 0.40 mm in width; aperture 0.10 to 0.12 mm in diameter.

Locality. Sumner, 13/5/03 (as described by Bale, 1924), Canterbury Museum Slide Nos. 51, 51A and 51B; Mussel Culvert, Heathcote Estuary (P.M.R.) 15/11/51, 250; Taylor’s Mistake, Christchurch (G. Knox) 7/9/48, 238.

Plumularia setacea (Ellis) var. opima Bale, 1924. Figs. 3, d; 4, b.

A variety of distinctive appearance as the nodes of the hydrocladia form deep constrictions, the internodes of both stem and hydrocladia are very wide in proportion to their length, the short internodes being almost, or, as wide as they are long and the hydrothecal internode abruptly and conspicuously swollen below the hydrotheca.

Stems up to 4.0 cm; stem internodes 0.30 to 0.575 mm in length and 0.18 to 0.21 mm in width; apophysis 0.07 to 0.10 mm in length; short athecate internodes 0.07 to 0.13 mm in length; longer thecate internodes 0.25 to 0.30 mm in length; hydrocladium 0.12 to 0.15 mm in width measured at the base of the hydrotheca; abcauline length of hydrotheca 0.06 to 0.10 mm; width of hydrotheca at the margin 0.12 to 0.14 mm and at the base 0.05 to 0.06 mm; nematothecae 0.05 to 0.06 mm in length and 0.025 mm in width at the aperture: gonotheca (female) 1.10 mm to 1.4 mm in length and, 0.40 to 0.50 mm in width; aperture approximately 0.10 mm in diameter.

Locality. Type locality Tomahawk Beach, Dunedin (Bale, 1924); selected type slide, Canterbury Museum Slide No. 52; paratype, Slide No. 52A; Little Papanui, on Gigartina sp. (E. J. Batham), 3/8/53, 425. A New Zealand variety.

I he following polysiphonic species P. brachiata and r. tenuissima are not represented in the present collection, and the figures are from British Museum (Natural History) material kindly shown me by Dr. W. J. Rees. Both are rare endemic species known only from the type locality. The species are distinguished by features of the stem internodes and the arrangement of the hydrocladia on the stem.

Plumularia brachiata Totton, 1930. Fig. 4, e, f.

1930. Plumularia brachiata Totton, p. 226, text-fig. 62, a-b.

A tall plumularian up to at least 30.0 cm in height and with a stem 3.0 x 4.0 mm in diameter; stem polysiphonic and irregularly branched; branches in one plane, up to 15.0 cm in length, directed towards the distal end of the stem and lying close alongside the stem; branches may carry a few branchlets; the secondary tubules usually run along the sides of the stem and branches that are without hydrocladia and arise from the axils of the hydrocladia; the secondary tubules may be “ transformed into branches which repeat the characters of the main stem”; transverse section of the stem elliptical; hydrocladia alternate, very delicate, approximately 5.0 mm in length, carried on an apophysis at the distal end of the internode; apophyses 0.20 to 0.22 mm in length, with the lower side greatly thickened and a subterminal thickened ring of perisarc; a prominent tubular “ mamelon ” at the distal end of the apophysis and with the aperture facing upwards; nodes of stem transverse, irregular so that the internodes carry from one to four apophyses; stem internodes 0.82 to 1.88 mm in length and 0.18 to 0.20 mm in width; nodes of the hydrocladia oblique, dividing each hydrocladium into short athecate internodes and longer thecate internodes; short athecate internodes 0.11 to 0.16 mm in length; long thecate internodes 0.20 to 0.32 mm in length; width of hydrocladia 0.05 to 0.07 mm; one, or sometimes two, short internodes between the apophysis and the first thecate internode; a proximal and distal septal ridge on each short internode and, on the longer internode, in addition to these, a ridge between the proximal ridge and the base of the hydrotheca, a ridge at the level of the hydrothecal margin and another between the hydrothecal margin and the distal ridge; hydrotheca in the middle of the internode, campanulate, with the adcauline side fixed to the internode and slightly shorter than the abcauline side; margin entire, smooth, slightly everted and sloping down slightly at the back to meet the internode; abcauline wall 0.070 to 0.073 in length; hydrotheca 0.077 to 0.080 mm in width at the margin (lateral view) and 0.055 mm at the base; nematothecae, bithalamic, conical, 0.080 to 0.110 mm in length and 0.040 to 0.050 mm in width at the margin; usually a lateral nematophore just above the origin of the hydrocladium; a row of

nematothecae on either side of the secondary tubules; a pair of nematothecae flanking each apophysis; a terminal pair beyond the “ mamelon ” on each apophysis; a median nematotheca on each short internode, and, on each long internode, a median infrathecal nematotheca, and a suprathecal lateral pair, which are usually longer than the median nematotheca, reaching almost to the end of the internode: gonothecae short, cornuate with the distal end obliquely truncated and with a wide circular operculum; the gonothecae lie close alongside the stem and are borne singly on the sides of the stem apophyses; gonotheca 0.77 to 0.89 mm in length and 0.32 to 0.37 mm in maximum diameter.

Locality. Type locality, off North Gape, New Zealand, 70 fathoms (Totton, 1930). Species known only from the type locality.

Phimularia tenuissima Totton, 1930. Fig. 4 g, h.

1930. Phimularia tenuissima Totton, 1930, p. 228, Text-fig. 63, a-b

A plumularian species described from a stem fragment 1.0 cm in length; stem polysiphonic, branched, and rebranched in one plane; branches directed towards the distal end of the stem and lying close alongside the stem; the secondary tubules of the stem (and branches) usually run along the sides of the stem and branches that are without hydrocladia and arise from the axils of the hydrocladia; hydrocladia, carried on an apophysis, clearly alternate at the distal end of the branches, but elsewhere often sub-opposite and decussate; apophysis 0.15 mm in length; a prominent tubular “ mamelon ” at the distal end of the apophysis with the aperture facing upwards; stem without nodes, stem diameter 0.11 mm; nodes of the hydrocladia oblique, dividing the hydrocladia into short athecate internodes and longer thecate internodes; short athecate internodes 0.11 to 0.19 mm in length; longer thecate internodes 0.37 mm in length; hydrocladia narrow, 0.04 mm in width; the basal short internode of the hydrocladium is not divided from the stem apophysis; a proximal and distal septal ridge on each short and long intemode of the hydrocladium; hydrotheca approximately in the middle of the internode, campanulate, with all the adcauline side fixed to the internode, and slightly shorter than the abcauline side; margin entire, smooth, everted slightly and sloping down gradually at the back to meet the internode; abcauline wall 0.05 mm in length and 0.06 mm in width at the margin, viewed laterally, and 0.04 mm in width at the base; nematothecae bithalamic, conical, 0.07 to 0.08 mm in length and 0.045 mm in diameter at the margin; a row of nematothecae on either side of the secondary tubules; stem without nematothecae, except for one (? a pair) flanking the apophysis in the axils of the hydrocladia; a median nematotheca on each short internode; on each longer internode a subhydrothecal median nematotheca, and a lateral pair of suprathecal nematothecae longer than the median but not extending to the end of the internode: gonotheca “ incomplete, without nematothecae, straight, compressed, distal end truncated, with wide aperture ”; gonotheca 0.33 mm in length and 0.18 mm in maximum width; aperture 0.15 mm in width.

Locality. Type locality off Three Kings Islands, New Zealand, 300 fathoms (Totton, 1930). Species known only from the type locality.

The three following species P. spinulosa Bale, P. pulchella Bale, and P. hyalina Bale are at once recognized from all other New Zealand species of Plumularia as they possess hydrocladia that carry only a single hydrotheca. Of the group, P. hyalina is the best known from out coastal waters, ranging over approximately 11 0 of latitude from the Bay of Islands in the North Island, to Bluff in the South Island, and is also known within this latitudinal range from the outlying Chatham Islands. As at present known in New Zealand P. spinulosa is a North Island species and P. pulchella a South Island species. P. pulchella is very similar in growth habit and morphology to P. hyalina, but the latter lacks nematothecae in the axil of the hydrocladium.

Plumularia spinulosa var. spinulosa Bale, 1882. Fig, 4, i and j.

1882. Plumularia spinulosa Bale, p. 30, pi. 15, fig. 8. 1884. Plumularia spinulosa Bale. Bale, p. 139, pi. XII, figs. 11, 12. 1908. Plumularia spinulosa Bale. Warren, p. 320. 1923. Monotheca spinulosa var. typica Stechow, p. 225 (synonymy). 1958. Plumularia spinulosa var. typica Bale. Millard, p. 212 (synonymy). 1959. Plumularia spinulosa Bale. Pennycuik, p. 180.

A tiny plumularian with monosiphonic stem up to 2.5 mm in height, with internal chitinous pegs or rings in the hydrorhiza and regularly alternate very short hydrocladia arising about the middle of the internode; each hydrocladium carries a single hydrotheca; basal two or three stem internodes without a branch and with one or two annuli; nodes

oblique, regular and clearly recognizable; stem internodes 0.19 to 0.275 mm in length and 0.05 to 0.07 mm in width; occasionally a proximal and/or distal septum on the stem internodes; stem apophysis 0.05 to 0.06 mm in length; two hydrocladial internodes only, one short and one long bearing the hydrotheca; long internode curved distally and contracted on the inner side behind the hydrotheca and extending beyond the rim of the hydrotheca into a short, bluntly pointed spine; short internode of hydrocladium 0.05 to 0.07 mm in length; long internode of hydrocladium 0.20 to 0.25 mm in length; hydrothecae rounded at the base, laterally compressed, and aperture at right angles to the long axis of the internode; margin slightly everted on the abcauline side, and slightly sinuous towards the adcauline side; distinctive, large, intrathecal fold arising about the middle of the adcauline side and extending approximately halfway across the hydrotheca; length of abcauline side 0.15 to 0.18 mm; maximum width which is at the margin of hydrotheca, 0.15 to 0.22 mm; nematothecae bithalamic, canaliculate with slender base; one nematotheca on the lower part of the stem internode on the side opposite the hydrocladium, one in the axil of each hydrocladium, one below each hydrotheca and one at each side above the hydrotheca; nematothecae above the hydrotheca and in the axil of hydrocladium with the upper chamber laterally compressed and the whole convex upper margin open, nematothecae, 0.05 to 0.07 mm in length; 0.025 to 0.04 mm at the aperture: gonothecae, more or less cylindrical, but tapering proximally into a short, narrow stalk, distal end truncated with everted margin and aperture broad, covered by an operculum; walls smooth or very slightly and irregularly undulated; length of gonotheca including stalk, approximately 1.25 mm; stalk, 0.10 mm in length; maximum width (at everted margin), 0.50 mm approximately.

Locality. Type locality, Queenscliff, Victoria, Australia (Bale, 1882): Coromandel, Coromandel Peninsula (G. Trevarthen) 18/5/50, 716; Island Bay, Cook Strait, drift (Gram), 31/3/52, 289; Makara Beach, drift (V. Cassie), 25/8/52, 304.

Distribution. Australia; New Zealand; South Africa; Lord Howe Island; Japan as var, obtusa Stechow, 1923.

Plumularia pulchella Bale, 1882. Fig. 5, c-e.

1882. Plumularia pulchella Bale, p. 30, pi. XV, fig. 6. 1884. Plumularia pulchella Bale. Bale, p. 140, PI. XII, fig. 6; PI. XIX, fig. 37. 1894. Plumularia flexuosa Bale, p. 115, PI. 5, figs. 6-10. 1925. Plumularia ( Monotheca ) flexuosa Bale. Stechow, p. 499. 1928. Plumularia pulchella Bale. Trebilcock, p. 24. 1930. Plumularia pulchella Bale. Totton, p. 221, fig. 58 a-d. 1950. Plumularia pulchella Bale. Hodgson, p. 41, fig. 72. 1957. Plumularia pulchella Bale. Millard, p. 232. 1959. Plumularia pulchella Bale. Pennycuik, p. 180.

A small plumularian with monosiphonic stem up to 15.0 mm in height; the inner walls of the hydrorhiza with chitinous pegs or rings of thickening and the stem with regularly alternating very short hydrocladia arising about two-thirds of the way up the internode; each hydrocladium carries a single hydrotheca; basal one or two internodes short (about half the length of those above), athecate and with from one to three annuli and often a nematotheca; stem nodes transverse, regular, and clearly recognizable; stem internodes swollen at the distal extremity; 0.20 to 0.35 mm in length and 0.07 to 0.10 mm in width; stem internodes often with walls wrinkled internally; occasionally stem internodes with one or two transverse septa; stem apophyses approximately 0.05 mm in length; hydrocladial internodes two in number only, one athecate short internode, and a long thecate internode; short internode 0.05 to 0.10 mm in length; long internode curves abruptly distally from under the hydrotheca, widening towards the summit; one to three constrictions on the internode behind the hydro theca; long internode 0.12 to 0.25 mm in length; hydrotheca campanulate, a smooth slightly everted margin; rim of hydrotheca extends slightly beyond the end of the internode; aperture horizontal at right angles to the long axis of the internode; length of abcauline side of hydrotheca 0.08 to 0.12 mm; a distinct submarginal contraction and thickening on the abcauline side of the hydro theca; maximum width, which is at the margin of the hydrotheca, 0.09 to 0.14 mm; nematothecae bithalamic, canaliculate, with slender bases; one nematotheca below each hydrotheca, one on each side arising from distal end of the internode above the hydrotheca and extending well above the rim of the hydrotheca, and two in the axil of each hydrocladium; nematothecae 0.05 to 0.06 mm in length; 0.035 to 0.045 mm in width at the aperture; gonotheca six or seven times the length of the hydrotheca, ovate obliquely truncate distally; large smooth internal teeth just below the aperture; length of gonothecae approximately 0.60 mm; width 0.290 to 0.375 mm.

Locality. Type locality, Queenscliff, Victoria, Australia (Bale, 1882): off North Cape Stn. 134 “Terra Nova” 11-20 fathoms (Totton, 1930); Menzies Bay, Christchurch

(S. Rind), 26/8/51, 202; Portobello Marine Biological Station, reef (E. J. Batham), 14/2/51, 70; Channel between Quarantine Island and Portobello M.B.S. approx. 2 fathoms (P.M.R.), 30/11/51, 258; Bluff (Trebilcock, 1928).

Distribution. Australia; New Zealand; South Africa.

Plumularia hyalina Bale, 1882. Fig. 5, a-b.

1882. Plumularia hyalina Bale. 1884. Plumularia hyalina Bale. Bale, p. 141, PI. XII, figs. 4, 5. 1928. Plumularia hyalina Bale. Trebilcock, p. 24, PI. VI, fig. 6.

A small plumularian with monosiphonic stem up to 20.0 mm in height, with inner wall of hydrorhiza with deep transverse undulations and the stem with regularly alternate very short hydrocladia arising close to the distal end of the internode; each hydrocladium carries a single hydrotheca; basal two or three stem internodes without a branch, and with one or two transverse annuli; nodes regular, and clearly recognizable; nodes forming proximal termination of internode slightly oblique, those forming the distal termination transverse; stem internodes 0.45 to 0.50 mm in length and 0.13 to 0,25 mm in width; stem internodes with from one to four thick transverse septal ridges; stem apophysis approximately 0.03 mm in length; two hydrocladial internodes only, one short and one long, that bears the hydrotheca; short internode 0.10 to 0.12 mm in length, long internode curving distally from under the hydrotheca, smooth incurved at the summit and not extending beyond the rim of the hydrotheca; long internode of hydrocladium 0.31 to 0.40 mm in length; hydrotheca ventricose, the adcauline side bent backwards at the distal end of the internode forming a cavity which is occupied by two nematothecae; aperture of hydrotheca at right angles to the long axis of the hydrocladium and with a broad notch on the adcauline side; length of abcauline side 0.18 to 0.20 mm; maximum width, which is at the margin of the hydrotheca 0.15 to 0.18 mm; hydranth with about 20 tentacles; nematothecae bithalamic, canaliculate, with slender bases; usually one nematotheca arising from a slightly dome-shaped prominence below each hydrotheca, but this nematotheca may be absent; one nematotheca at each side behind the hydrotheca; nematotheca 0.055 to 0.06 mm in length; and 0.031 to 0.035 mm in width at the aperture: gonotheca (juvenile) more or less pear-shaped, but distal end broadly truncated and nearly flat; width of truncated distal end 0.50 to 0.65 mm; mature gonotheca more elongate, 1.30 to 1.70 mm in length including the stalk; stalk 0.15 mm in length; terminal aperture approximately 0.31 mm in width.

Locality. Type locality, Queenscliff, Victoria, Australia (Bale, 1882): Russell, Bay of Islands on Carpophyllum sp. (G. Trevarthen) 22/8/50, 715; Browns Bay, Auckland (P.M.R.), 9/2/53, 370; St. Helier’s Bay, reef, Auckland (C. Trevarthen), 3/6/50, 714; Ohope Beach, Whakatane, on drift seaweed (P.M.R.), 12/2/53, 328; Palliser Bay, Cook Strait, on crayfish appendage (R. W. Zander), 6/9/56, 498; Island Bay (Trebilcock, 1928); Taylor’s Mistake, Christchurch (G. Knox), 13/9/50, 232; Portobello Marine Biological Station, reef (E. J. Batham), 13/12/52, 721; Little Papanui, Otago, on Cystophora (E. J. Batham), 14/5/53, 420; St. Clair, Dunedin, Trebilcock, 1928; Bluff (Trebilcock, 1928); Station 26, Waitangi, intertidal (Chatham Expedition, 1954), 30/1/54, Chatham Expedition Slide No. 19.

Distribution. Australia; New Zealand.

Plumularia triangulata Totton, 1930. Fig. 5, f-g. 1930. Plumularia triangulata Totton, p. 225, Text-fig. 61

A small plumularian with stem up to 7.0 mm in height, simple or sparingly branched, monosiphonic with the alternate hydrocladia carried on an apophysis at the distal end of the internode; apophysis with a small “ mamelon ” in the centre of the upper surface; apophysis approximately 0.15 mm in length; nodes of the stem transverse; stem internodes approximately 0.80 mm in length and 0.25 mm in width measured at the node; nodes of the hydrocladia slightly oblique dividing the hydrocladium into thecate internodes of approximately equal length; length of the hydrocladial internodes about 0.80 mm; width of hydrocladial internodes 0.09 mm, measured at the node; hydrocladial internodes lack septal ridges; hydrotheca campanulate carried about the middle of the internode, and with a greater diameter than depth; margin entire, smooth, and very slightly everted; abcauline length of hydrotheca approximately 0.08 mm; width at the margin, viewed laterally, approximately 0.10 mm and at the base of the hydrotheca approximately 0.07 mm; nematothecae monothalamic, straight on the inner side and convex on the outer side; aperture of the nematotheca oblique, sloping towards the stem or hydrocladium; a nematotheca near each end of the stem internodes; and one or occasionally two nematothecae at the distal end of each apophysis; one median infrathecal and one median suprathecal nematotheca; nematothecae 0.05 to 0.062 mm in length; aperture approximately 0.012 mm in width; gonothecae

triangular in transverse section, arising from the apophysis on the side opposite the “ mamelon ” and lying parallel to the stem; gonotheca approximately 2.20 mm in length and 0.70 mm in maximum width.

Locality. Type locality, off Three Kings Islands, New Zealand, 300 fathoms (Totton, 1930). Species known only from the type locality. P. triangulata is not represented in the present collection and the figures are drawn from British Museum (Natural History) material. This is the only species of Plumularia in New Zealand waters that has monothalamic, fixed nematothecae.

Halopteris Allman, 1877.

Erect stem thecate, carrying hydrocladia usually on an apophysis of the stem internode; a transverse node between the stem apophysis and the hydrocladia; hydrocladia on two sides of the stem and in one plane; hydrothecae with a pair of nematothecae on either side and these frequently carried on an apophysis of the internode.

The four species of Halopteris described below have previously been recorded from New Zealand and all are represented in the present collection. Two of them, H. minuta (Trebilcock, 1928) and H. heterogona (Bale, 1924) are endemic as is the varietal form zelandica Totton, 1930 of H. campanula (Busk, 1852). The varietal form campanula of the latter species is not known from New Zealand, but from Australia, Tasmania, Torres Strait, and the Indonesian region in the Southern Hemisphere, and Japan and the Red Sea in the Northern Hemisphere.

Halopteris constricta and H. minuta are very similar in erect stem characters, and it is possible that as they become better known H. constricta will be found to be a taller, more slender vaiety of H. minuta. Totton, when describing 11. constricta in 1930, did not discuss it relative to H. minuta (Thecocaulus minutus Trebilcock) but to “Nutting’s P. alternitheca” only from which species he concluded it was distinguished by differences in the shape of the hydrotheca and nematothecae. [? P. alternitheca a misprint for P. alternata Nutting, 1900.] The specimens in the present collection here recognized as H. constricta are similar to those described by Totton and the scoop-shaped mesial nematothecae with little or none of the adcauline side free from the internode at once distinguish H. constricta from “P. alternata” (now recognized and figured by Fraser [(1938, PI. 14, fig. 71, a) as H. diaphana (Heller) ] as the mesial nematothecae of the latter species are shaped like a wine-glass and have the adcauline side completely free from the internode.

Young, and ripe gonophores of H. constrict a were found for the first time on specimens in the present collection from Auckland. The female gonothecae are readily distinguished from the gonothecae of H. heterogona and H. campanula because of the downward curve of the distal end, and the distal aperture. The gonothecae of H. minuta are unknown.

H. campanula var. zelandica is the best known species of Halopteris in New Zealand waters and ranges from North Gape to Otago on the east coast and Chalky Inlet, on the west coast of the South Island, and is known also from the outlying Chatham Islands. H. minuta is known from a few localities in both North and South Islands, H. constricta from the North Island and H. heterogona from the far North of the New Zealand mainland and the outlying Three Kings Islands. All the material of H. heterogona and H. campanula var. zelandica has been dredged and the latter species is known down to 300 fathoms off the Otago coast. Both H. constricta and H. minuta are known from the intertidal and sublittoral regions.

Key to the Species of Halopteris in New Zealand

1 (4) Hydrocladia divided into alternating athecate and thecate internodes.

2 (3) Athecate internodes narrow, clearly longer than wide in all regions of the hydrocladia; hydro thecae longer than wide

H. constricta Totton, 1930

3 (2) Athecate internodes except proximal internode almost as wide as long; abcauline wall distinctly thickened and septal ridges often present; length to width ratio of hydrotheca somewhat variable, length either slightly greater than width, or length and width almost equal ...... H. minuta (Trebilcock, 1928)

4 (1) Hydrocladia divided into thecate internodes only. 5 (6) Paired nematothecae flanking hydrotheca either arising from a shelf-like structure, or a rounded apophysis of the internode and extending beyond the hydrotheca; no single mesial nematotheca above the hydrotheca H. heterogona (Bale, 1924)

6 (5) Paired nematothecae flanking hydrotheca on a tiny apophysis of the internode, short, and extending approximately half the way up the free adcauline wall of the hydrotheca; a single median nematotheca above the hydrotheca; nematothecae truncated, with inrolled sides; one mesial nematotheca above each stem hydrotheca. H. campanula (Busk, 1852) var. zelandica Totton, 1930: Distal chamber of nematothecae scoop-shaped; two mesial nematothecae above each stem hydrotheca.

Halopteris constricta Totton, 1930. Fig. 6, a-e.

1930. Halopteris constricta, Totton, p. 217, Text-fig. 56, a.

A tiny species with erect stems up to 9.0 mm in height; stems arising singly from a flattened strap-like hydrorhiza bearing long, tubular nematothecae and strengthened internally by chitinous pegs; base of stem for approximately 3.0 mm lacking hydrothecae and hydrocladia, with from one to three transverse nodes, and with one or two nematothecae; basal athecate region marked off from the rest of the stem by an oblique node; stems monosiphonic, either simple or with hydrocladia arising from the main stem, one per internode, and regularly alternate, except for the basal pair of hydrocladia which are frequently opposite and on the same stem internode; hydrocladia on taller stems may have secondary branch-hydrocladia arising from the primary hydrocladia in the same manner as the primary hydrocladia arise from the stem; hydrocladia arising from the front of the stem at the side of a hydrotheca; hydrocladia carried on a well developed apophysis of the stem internode and with from two to six hydrothecae; medial and distal stem regions and hydrocladia divided into short athecate, and longer thecate internodes by nodes that are alternately transverse and oblique; distal node of thecate internode transverse, that of athecate internode steeply oblique; hydrotheca carried about the middle of the internode; athecate stem internodes 0.15 to 0.175 mm in length; thecate internodes 0.26 to 0.35 mm in length; athecate hydrocladial internodes 0.10 to 0.125 mm in length; usually two athecate hydrocladial internodes between stem apophysis and the first thecate internode of the hydrocladium, and of these, the distal athecate internode the longer; thecate internodes of hydrocladia approximately 0.21 mm in length; width at base of stem approximately 0.10 mm measured at the base of the hydrotheca, and width of hydrocladia approximately 0.08 mm; hydrothecae large, longer than broad, set at an angle of approximately 40° to the internode axis; adcauline side of hydrotheca free from the internode from J to J the adcauline length; free adcauline side and lateral walls slightly constricted just below the margin otherwise hydrotheca almost cylindrical; margin smooth entire; abcauline length of hydrotheca 0.15 to 0.20 mm; length of free adcauline wall 0.06 to 0.075 mm; nematothecae bithalamic, canaliculate, and scoop-shaped; nematothecae 0.09 to 0.10 mm in length and 0.05 to 0.06 mm in maximum width; largest nematothecae are the laterals flanking the hydrotheca; mesial, non-paired nematothecae with little or no free adcauline wall; each hydrothecate internode with a basal subhydrothecal mesial nematotheca and two larger nematothecae arising from a small apophysis, flanking the hydrotheca, and reaching the level of the hydrothecal margin; each athecate internode except the proximal internode of the hydrocladium, with a single mesial nematothecae; occasionally there may be an extra mesial nematotheca above the hydrotheca and also two on the athecate internodes instead of one; a single nematotheca in the axil of each hydrocladium; gonotheca—(female), gonothecae in pairs between the mesial nematotheca and the base of the stem hydrothecae and occasionally below the hydrocladial hydrothecae; obovate, with the distal end curved round so that the lateral opening faces outwards and slightly downwards; aperture with dome-shaped operculum; terminal plug of coensarc surrounding thickened intragonothecal folds below and to the side of the aperture; gonotheca carried on a pedicel of two segments; two nematothecae on the base of the gonotheca just above the distal segment of the pedicel; length of female gonotheca excluding the pedicel, 0.91 to

1.0 mm; maximum width of gonotheca approximately 0.42 mm; length of pedicel, 0.10 mm and width of aperture 0.15 mm; (?) male gonotheca (Fig. 6, a), shorter, and narrower than female, carried on a pedicel of two segments and with two basal nematothecae; length 0.60 to 0.65 mm and width 0.33 to 0.40 mm.

Locality. Type locality, off Gape Maria van Diemen, N.Z., 35-40 fathoms (Totton, 1930): Glendowie, Auckland, on Sargassum (G. Trevarthen) -/10/49, 730; Island Bay, Cook Strait, on Paramithrax peronii (J. Yaldwyn), 2/10/54, 732.

Distribution. New Zealand; South Africa.

Millard (1957) describes H. constricta from South Africa with simple stems and stems with secondary hydrocladia arising from the primary hydrocladia. All the present colonies are as observed by Totton (1930) —i.e., with a main stem giving rise to non-branched primary hydrocladia only.

Halopteris minuta (Trebilcock, 1928). Fig. 6, f.

1928. Thecocaulus minutus Trebilcock, p. 25, PI. VII, fig. 6,6 a.

A tiny species with erect stems up to 6.0 mm in height; stems arising singly from a flattened strap-like hydrorhiza 0.10 to 0.15 mm in width, strengthened internally by chitinous pegs; base of stems for up to 1.0 mm lacking hydrothecae and hydrocladia and with two or three transverse nodes; basal athecate region marked off from the rest of the stem by an oblique node; stems monosiphonic with regularly alternating hydrocladia, one per hydrothecate internode, except for the basal pair of hydrocladia which are frequently opposite and on the same stem internode; hydrocladia arising from the front of the stem at the side of a stem hydrotheca; hydrocladia carried on a well developed apophysis of the stem internode; medial and distal stem and hydrocladia divided into short athecate and longer thecate internodes by nodes that are alternately transverse and oblique; distal node of thecate internode transverse, that of athecate internode steeply oblique; hydrothecae carried on the proximal third of the internode; athecate stem internodes approximately 0.15 mm in length; thecate stem internodes approximately 0.20 mm in length; athecate hydrocladial internodes 0.05 to 0.10 mm in length, well defined but rather short and bulging at the base on the abcauline side; usually two athecate internodes between the stem apophysis and the first thecate internode of the hydrocladium, and of these, the distal athecate internode the longer; width of stem measured at the base of the hydrotheca 0.10 to 0.11 mm; length of thecate internodes of hydrocladia approximately 0.25 mm; width of the hydrocladia approximately 0.125 mm; hydrothecae large, broadly campanulate, usually longer than broad, but some almost as wide as long; hydrothecae set at an angle of approximately 40° to the internode axis; adcauline side of hydrotheca free of the internode for one-half to two-thirds of its length; free adcauline side slightly concave; abcauline wall straight; margin smooth and entire; abcauline length of hydrotheca 0.125 mm; length of free adcauline wall 0.07 mm and length of fixed adcauline wall 0.11 mm; width of hydrotheca at the margin 0.5 mm; nematothecae bithalamic, canaliculate, narrow at the base, and with the abcauline side of the distal cup higher than the adcauline; nematothecae 0.06 to 0.08 mm in length and 0.025 to 0.05 mm in maximum width; largest nematothecae are the laterals flanking the hydrotheca; mesial non-paired nematothecae with little or no free adcauline wall; each hydrothecate internode with a basal subhydrothecal mesial nematotheca and two larger nematothecae arising from a small apophysis, and almost reaching the level of the hydrothecal margin; occasionally the stem thecate internodes with a single mesial suprahydrothecal nematotheca; each athecate internode except the proximal internode of the hydrocladium, with a single mesial nematotheca; a single nematotheca in the axil of each hydrocladium: gonotheca unknown.

Locality. Type locality, St. Glair, Dunedin (Trebilcock, 1928): Russell, Bay of Islands, intertidal on Carpophyllum sp. (G. Trevarthen), 21/8/50, 729; Tolaga Bay, east coast, North Island, storm drift (P.M.R.), 15/12/53, 377.

Halopteris heterogona (Bale, 1924). Fig. 6, h-i.

1924. Thecocaulus heterogona Bale, p. 255, fig. 13. 1928. Thecocaulus heterogona Bale. Trebilcock, p. 25. 1930. Halopteris heterogona (Bale). Totton, p. 217, text-fig. 56, b-d.

A tall species with erect stem up to 15.0 cm in height, stems growing in tufts from intertwining hydrorhizal fibres; stems monosiphonic, with regularly alternating hydrocladia one per internode, except for the basal pair which are opposite and on the same internode; hydrocladia arising from the front of the stem at the side of the hydrothecae; base of stem for approximately 1.50 cm lacking hydrothecae and hydrocladia and with two or three transverse nodes; basal athecate region marked off from the rest of the stem by two closely approximated steeply oblique nodes (“hinge joints”, Totton, 1930); between the two hinge joints is the first stem hydro-

theca and arising laterally, a pair of opposite hydrocladia; hydrocladia carried on an apophysis of the stem internode; nodes oblique, well developed, dividing both the stem and the hydrocladia into regular internodes; all internodes with a hydrotheca except those at the base of the stem and the first hydrocladial internode above the apophysis; hydrothecae arising about the centre of the internode; stem internodes 0.60 to 0.75 mm in length and 0.45 to 0.60 mm in width measured at the base of the hydrotheca; hydrocladial internodes 0.45 to 0.60 mm in length and 0.20 to 0.21 mm in width at the base of the hydrotheca; hydrothecae large, deeply campanulate, set at an angle of approximately 45° to the long axis of the internode; approximately one-third of the adcauline wall free from the internode; free adcauline wall slightly but recognizably concave; abcauline wall straight or slightly concave; margin smooth, entire, with outward flare on the abcauline side; abcauline length of hydrotheca 0.16 mm; length of fixed adcauline wall 0.125 mm; length of free adcauline wall 0.08 mm, width of hydrotheca at margin 0.125 mm; nematothecae bithalamic, canaliculate, more or less moveable, scoopshaped, particularly the mesial subhydrothecal nematotheca in which the adcauline side of the distal cup is much lower than the abcauline; nematothecae 0.10 to 0.16 mm in length and 0.05 to 0.07 mm in width at the aperture; largest nematothecae are the paired laterals flanking the hydrotheca and these increase in size from the proximal to the distal region of the stem; approximately five mesial nematothecae below the proximal hinge joint; each hydrothecate internode distal to this joint has a relatively small subhydrothecal nematotheca and two larger nematothecae flanking the hydrotheca, and either arising from a lateral expansion of the internode at its junction with the free adcauline wall, or arising from a small apophysis (Totton, 1930, fig. 56, b); on the stem the hydrothecal nematotheca in the axil of the hydrocladium smaller than that on the opposite side of the hydrotheca; occasionally, a second or third pair of nematothecae above the lateral hydrothecal nematothecae of the stem internodes; a minute bract-like nematotheca in the axil at the back of the hydrotheca; gonotheca—male and female gonothecae on the same stem; male gonotheca arising from a small pedicel of one segment, elongate oval in shape very small, not much longer than the hydrotheca and about half the width of the latter; male gonotheca lacking nematothecae; length of male gonotheca approximately 0.30 mm; width approximately 0.12 mm; female gonotheca large, borne on a pedicel of two segments, laterally flattened, distal end truncated; aperture with elliptical operculum; nematothecae, three to five in number, in a transverse arc at the base of the gonotheca; length of female gonotheca 2.20 to 2.50 mm in length; maximum width 0.80 to 1.0 mm; width of truncated distal end approximately 0.75 mm.

Locality. Type locality, off Cape Maria van Diemen, N.Z., 10 miles N., 50 fathoms (Bale, 1924); off Gape Maria van Diemen, “Terra Nova” Stn. 144, 35-40 fathoms (Totton, 1930); off Three Kings Islands, 100 fathoms, “ Terra Nova” Stn. 90 (Totton, 1930).

Halopteris campanula (Busk) var. zelandica Totton, 1930. Fig. 6, g.

1930. Halopteris campanula var. zelandica Totton, p. 219, text-fig. 57, a

Erect stems up to 6.0 cm and monosiphonic; basal two or three stem internodes athecate and separated by transverse nodes; one to four proximal hydrothecate internodes with opposite hydrocladia arising from the side of the hydrotheca; hydrocladia alternately arranged in the medial and distal region, one per stem internode; hydrocladia carried on a very small apophysis of the stem internodes; nodes well defined, steeply oblique on both stem and hydrocladia; stem internodes 0.80 to 1.30 mm in length and 0.18 to 0.25 mm in width measured at the base of the hydrotheca; internodes of hydrocladia 0.60 to 0.80 mm in length and 0.19 to 0.25 mm in width; hydrothecae large, campanulate, carried at the proximal end of the internode and set at an angle of approximately 60° to the axis; abcauline and adcauline sides approximately parallel; about half the length of the adcauline side of the hydrotheca free from the internode; abcauline wall thicker than adcauline and thickening continued down to the mesial subhydrothecal nematotheca; length of abcauline wall 0.25 to 0.30 mm; length of free adcauline wall 0.11 to 0.18 mm and length of fixed adcauline wall 0.15 to 0.18 mm; width of hydrotheca at the margin 0.25 to 0.29 mm; nematothecae bithalamic, paired lateral nematothecae 0.10 to 0.125 mm in length and 0.07 to 0.10 mm in maximum width; mesial nematothecae 0.07 to 0.10 mm in length and 0.03 to 0.04 mm in width; chamber of nematotheca rounded and scoopshaped on the abcauline side; on each hydrocladial hydrothecate internode a single mesial nematotheca below the hydrotheca and another above the hydrotheca; median nematothecae with a broad basal region; one lateral nematotheca on a small apophysis, at each side of the hydrotheca; a single mesial nematotheca on the proximal internode of the hydrocladium; usually two, but occasionally one, unpaired mesial suprathecal nematothecae on the stem internodes: gonotheca not known for variety zelandica.

Locality. Type locality, North Cape, N.Z., 11-20 fathoms (Totton, 1930): 3 miles offshore, Doubtless Bay, on submarine cable (E. O. Poole; G. S. “Matai”) 14/8/51, 188; Cook Strait, Stn. 4, off Rangitoto Island, 40-50 fathoms (V.U. Zool Dept.), 18/12/54, 571; Otago,

Canyon B/C, Stn. 55/9, 300 fathoms (E. J. Batham), 16/8/55, 613; Chalky Inlet, North Port, 8-10 fathoms, (“New Golden Hind” Exped.), 4/2/46, 191; Paterson Inlet, Stewart Island, 18 fathoms, Stn. 20 “Alert” (W. H. Dawbin), 12/1/52, 615; N. of The Sisters, Stn. 23, approx. 33 fathoms (Chatham Expedition, 1954), 29/1/54, Chat. Exped. Slide No. 23; between South-East and Pitt Island, Stn. 37, 30 fathoms (Chatham Exped. 1954), 2/2/54, Chat. Exped. Slide No. 23a.

Halopteris campanula var. campanula (Busk, 1852)

1852. Plumularia campanula Busk, p. 401. 1896. Plumularia campanula Busk. Farquhar, p. 466. 1915. Plumularia campanula Busk. Bale, p. 295 (synonymy). 1921. Schizotricha campanula (Busk). Bedot, p. 12. 1930. Halopteris campanula (Busk). Totton, p. 217, text-fig. 57, b. 1942. Schizotricha campanula (Busk). Blackburn, p. 107. 1950. Plumularia campanula Busk. Hodgson, p. 40, fig. 69. 1959. Halopteris campanula (Busk). Pennycuik, p. 177.

A medium to tall species with simple, monosiphonic, or polysiphonic erect stem; polysiphonic stems up to 12.0 cm in length, others usually shorter, about 6.0 cm or less; polysiphonic stems branched, branches slender, bearing hydrothecae and alternately arranged hydrocladia; hydrocladia on polysiphonic stems either arising from each branch internode, or, every second internode; hydrocladia carried on a very small apophysis of the branch; in simple stems hydrocladia arising directly from the hydrorhiza “ Antenella forms”, of Blackburn, 1942; in other monosiphonic stems the hydrocladia arise alternately from the internodes of the erect stem; nodes well developed and steeply oblique on stem, branches, and hydrocladia; internodes of stem, branches and hydrocladia usually long, and usually bearing a proximal hydrotheca except the first internode above the small stem or branch apophysis; hydrothecae large, campanulate, arranged at an angle of approximately 40° to the long axis of the internode; one third to one half the adcauline side free from the internode and slightly concave; abcauline side bulging a little towards the base and slightly concave below the margin; margin smooth, entire; nematothecae bithalamic; distal cup of nematotheca truncated with inrolled sides; on each hydrocladial hydrothecate internode a single mesial nematotheca below the hydrotheca and another above the hydrotheca; mesial nematothecae with a broad basal region; lateral nematothecae flanking the hydrotheca on a small apophysis; a single mesial nematotheca on the proximal internode of the hydrocladium; usually one, but occasionally two, unpaired mesial suprathecal nematothecae on the stem internodes; gonotheca—male and female gonothecae borne on the same stem; male gonotheca carried on a pedicel of a single segment; small, oblong, with a minute operculum covering the terminal aperture; a single nematotheca at the base of the gonotheca; female gonotheca larger, with a truncated distal end, and large, oval operculum covering the terminal aperture; two nematothecae on the base of the gonotheca above the two segments of the pedicel.

Locality. Type locality, Bass Strait, Australia (Busk, 1852).

Distribution. Australia, Tasmania, Torres Strait, Japan, East Indies, Red Sea.

Nemertesia Lamouroux, 1816

Erect stem athecate, carrying branches and hydrocladia on an apophysis of the stem internodes; a transverse node between the stem apophysis and the branch and hydrocladium; hydrocladia arranged in three or more series on more than one side of stem and branches; coenosarc of stem formed into several well developed canals.

Three species, N. antennina (Linnaeus, 1758), N„ cymodocea (Busk, 1851) and N. elongata Totton, 1930 are recorded from New Zealand. Of these species N. cymodocea is described from New Zealand for the first time. There is no specimen of the widely distributed N. antennina in the present collection and, it seems possible that the identification of this species from New Zealand waters is incorrect and that the material previously described as this species is either N. cymodocea or N. elongata. The latter species have tall, branched, polysiphonic stems, while the stems of N. antennina are unbranched and monosiphonic. In the Canterbury Museum “Hutton Slide Collection” there is a slide with two stem, or (?) branch fragments from Stewart Island, labelled Antennularia antennina (now generally recognized as a species of Nemertestia) . This slide is clearly recognizable as the polysiphonic N. elongata as it shows four hydrocladia per whorl and other features characteristic of the latter species. It must be noted, however, that Hutton gives

Lyall Bay, Wellington, as the locality of his specimens of A. antennina. Possibly more material came to hand before Goughtrey (1875) gave an extended description of specimens of A. antennina (some of which were undoubtedly sent him by Hutton) as Goughtrey notes differences between the description of “A.” antennina as given by Johnston (1847, p. 86) and the New Zealand specimens. The “ numerous branchlets ” and the “ non-jointed, distinctly wrinkled ” nature of the branches in Coughtrey’s New Zealand material indicate that he had N. elongata before him and not N. antennina.

Because it is very doubtful that Coughtrey’s specimens were N. antennina only a brief description of this well known species is given here for comparison with N. elongata and N. cymodocea. N. cymodocea is a Southern Hemisphere, probably circumpolar species, and N. elongata is an endemic species. As at present known both are sublittoral in range.

Key to the Species of Nemertesia in New Zealand

1 (2) Erect stem simple, generally not regularly branched but an occasional side shoot may occur; monosiphonic: six to nine hydrocladia per whorl N. antennina (Linnaeus, 1758)

2 (1) Erect stem branched, not simple; polysiphonic.

3 (4) Four hydrocladia per whorl; position of hydrocladia alternating in successive whorls (Fig. 5, h); distal region only of hydrocladium showing short athecate internodes and longer thecate internodes, otherwise hydrocladial internodes all carry a hydrotheca N. elongata Totton, 1930.

4 (3) Generally two hydrocladia per whorl, but number variable, sometimes three and occasionally only one; position of hydrocladia alternating in successive whorls; hydrocladium divided into short athecate internodes and longer thecate internodes throughout N. cymodocea (Busk, 1851)

Nemertesia antennina (Linnaeus, 1758) 1758. Sertularia antennina Linnaeus, p. 1310. 1816. Nemertesia antennina (Linnaeus). Lamouroux, p. 163. 1836. Antennularia indivisa Lamarck, p. 156. 1873. Antennularia antennina (Linnaeus). Hutton, p. 258. 1876. Nemertesia antennina (Linnaeus). Kirchenpauer, p. 51. 1896. ? Antennularia antennina (Linnaeus). Farquhar, p. 466 (N.Z. synonymy). 1900. Antennularia antennina (Linnaeus). Nutting, p. 69, PI. ix, figs. 1 and 2 (synonymy). 1946. Antennularia antennina (Linnaeus). Vervoort, p. 326.

A tall species up to 30.0 cm in height, the erect stems simple, rarely with a few irregular branches; stems monosiphonic growing in a cluster from a tangled mass of hydrorhizae; hydrocladia caried on an apophysis of the stem, incurved, a whorl of six to nine hydrocladia arising from the distal end of the internode; hydrocladia at distal end of stem not arranged in whorls but are alternate either one hydrocladium or a pair of hydrocladia to an internode; nodes of stem transverse, but not always clearly recognizable; nodes of hydrocladia slightly oblique, dividing the hydrocladium into alternate short athecate and longer thecate internodes; hydrothecae small, approximately in the middle of the internode, campanulate, with a smooth entire margin; nematothecae bithalamic, conical; one pair of nematothecae flank the base of each hydrocladium; one or two nematothecae are found on each short internode; a single nematotheca below each hydrotheca on the proximal region of the internode, and two nematothecae, one on each side immediately above the hydrotheca; gonotheca, arising from the axil of a hydrocladium, broadly oval, with short stalk and subterminal circular aperture, facing towards the stem.

Locality. Type locality, European Seas (Linnaeus): Lyall Bay, Wellington (Hutton, 1873, as Antennularia antennina; ? misidentification).

Distribution. Europe; Mediterranean; Adriatic; West Coast of Africa; Madeira Islands; Atlantic Coast of North America; Japan; (?) New Zealand.

Nemertestia elongata Totton, 1930. Figs. 5, h-i; 6, j. 1930. Nemertesia elongata Totton, p. 229, text-fig. 64.

A tall New Zealand plumularian up to 59.0 cm in height with polysiphonic athecate main stem and branches; the hydrocladia, up to 6.0 mm in length arise from the distal end of each stem and branch internode in alternating whorls of four; branches irregularly arranged, up to 9.0 cm in length and of similar structure to the stem, are found one or two centimetres apart towards the distal end of the stem as the lower branches are shed as growth proceeds; hydrorhizae forming a tangled mass of fine tubes; stem approximately 1.5 mm in diameter at the base; nodes of stem transverse, most readily seen in the distal region of the stem and branches; nodes of hydrocladia oblique and best seen at the base of each thecate internode; first short athecate internode of hydrocladium not divided from the apophysis; apophysis approximately 0.40 mm in length; stem internodes 0.40 to 1.0 mm in length and 0.20 to 0.25 mm in width; internodes of branches 1.10 to 1.20 mm in length and approximately 0.30 mm in width; frequently no distinction into short athecate and longer thecate internodes in the proximal region of the hydrocladium; proximal internodes of hydrocladium 0.35 to 0.45 mm in length; distal short athecate internodes approximately 0.11 mm in length; distal thecate internodes 0.25 to 0.36 mm in length; hydrocladia approximately 0.10 mm in width measured at the base of the hydrotheca; short internodes where distinguishable, usually with proximal and distal septal ridges; longer thecate internodes show in addition to the proximal and distal septal ridges three other ridges, one between the proximal ridge and the base of the hydrotheca, one at the level of the base of the hydrotheca and another above the hydrotheca and between it and the distal ridge; hydrothecae small, campanulate, with smooth entire margin, which viewed from the side forms a low convex curve from the front to the back of the hydrotheca; aperture at 90° to the long axis of the internode; abcauline length of hydrotheca approximately 0.07 mm; width viewed laterally, of hydrotheca at margin approximately 0.07 mm and width at the base 0.03 to 0.05 mm; a tall, distally directed tubular “ mamelon ” in the centre of the upper surface of each stem and branch apophysis; nematothecae bithalamic with the upper cup scoop-shaped, the outer side being the higher; depth of upper cup about one-third that of the lower tapering region; a pair of nematothecae flank the axil of the stem and branch apophyses; a single nematotheca on each short internode; when short internodes not distinguishable the hydrothecate internodes show two nematothecae below each hydrotheca with that nearer the hydrotheca arising from a well developed swelling of the internode; two laterally placed nematothecae above the hydrotheca reaching nearly to the end of the internode; nematothecae 0.075 to 0.10 mm in length and the upper cup 0.025 to 0.032 mm in width at the margin; gonothecae, carried on the apophysis of the branches, slightly curved, narrow at the base and obliquely truncated above, with wide circular aperture, the rim of which slopes towards the adcauline side; length of gonotheca up to 0.60 mm and up to 0.30 mm in width; width of aperture approximately 0.20 mm.

Locality. Type locality, off Three Kings Islands, New Zealand, 100 fathoms (Totton, 1930): off Cape Turakirai, Cook Strait, approx. 50 fathoms (M. Buchler), 9/4/60, 726. The present specimen is infertile and the description and figure of the gonotheca is from British Museum (Natural History) material.

Nemertesia cymodocea (Busk, 1851)- Fig. 6, k.

1851. Antennularia cymodocea Busk, p. 119. 1876. Nemertesia ( Antennularia) decussata Kirchenpauer, p. 52, PI. 11, fig. 24; PI. 111, fig. 24; PI. VII, fig. 24. 1890. Antennularia decussata Kirchenpauer. Marktanner-Turneretscher, p. 258, pi. VI, fig. 7. 1907. Antennularia hartlaubi Ritchie, p. 542, PI. 111, fig. 4, a-b. 1957. Nemertesia cymodocea (Busk). Millard, p. 234 (synonymy).

A tall species, with stem up to 49.0 cm in height, arising from a mass of small hydrorhizal tubes; main stem and branches athecate and polysiphonic; stem approximately 2.5 mm in width at the base; branches found towards the distal region of the stem and irregularly arranged; the hydrocladia up to 6.0 mm in length, arise in whorls from the distal end of each stem and branch internode, but whorls rather variable in arrangement; whorls frequently in alternate pairs, but there may be two alternating whorls of three hydrocladia per internode; no regularity as to the positional arrangement on stem or branches of the internodes with alternating whorls of two hydrocladia or those with alternating whorls of three hydrocladia; occasionally on some branches at the base of the stem there is one hydrocladium per internode alternately arranged and in one plane; hydrorhizae forming a mass of fine tubes; nodes of stem transverse, most readily seen in the distal regions of the stem and branches; nodes of the hydrocladia oblique and dividing each hydrocladium into short athecate internodes and longer thecate internodes; hydrocladia carried on an apophysis of the stem or branch; apophyses 0.25 to 0.40 mm in length; stem and branch internodes 0.85 to 1.25 mm in length and 0.20 to 0.30 mm in width; short internodes of hydrocladium

0.10 mm in length; one or two short athecate internodes may be present at the base of each hydrocladium between the apophysis and the first long internode; long thecate internodes of hydrocladium approximately 0.275 mm in length; hydrocladia 0.13 to 0.15 mm in width measured at the base of the hydrotheca; short and long hydrocladial internodes with septal ridges; short internodes usually with proximal and distal septal ridges; long internodes with septal ridge at the proximal and distal end and in addition, one between the proximal ridge and the base of the hydrotheca, one at the level of the base of the hydrotheca, and another above the hydrotheca and between it and the distal ridge; hydrothecae small, campanulate, with smooth entire margin, which viewed from the side forms a low convex curve from the front to the back of the cup; aperture at 90° to the long axis of the internode; abcauline length of the hydrotheca approximately 0.07 mm; width of the hydrotheca at the margin viewed laterally, 0.09 to 0.10 mm, and width at the base 0.05 mm; a well developed tubular “ mamelon ” more or less in the centre of the upper surface of each stem and branch apophysis; nematothecae bithalamic with the upper cup rather scoopshaped, the outer side being the higher; depth of upper cup about one-third that of the lower tapering region; a pair of nematothecae flank the axil of the stem and branch apophyses; a single nematotheca on each short internode; one nematotheca below each hydrotheca carried on a well formed swelling of the internode; two long nematothecae above the hydrotheca, one on each side and reaching nearly to the end of the internode; nematothecae 0.06 to 0.075 mm in length and upper cup 0.02 to 0.025 mm in width at the margin; gonothecae, elongate, oval, tapering distally to a neck and proximally to a short stalk; young gonothecae shorter and truncated at the distal end.

Locality. Type locality, Cape of Good Hope area; Cape Kidnappers, Hawke Bay (J. A. F. Garrick), —/4/53, 297; off Palliser Bay, Cook Strait, Stn. 15, 100-150 fathoms, also Stn. 55, 40-100 fathoms, Stn. 96, approx. 380 fathoms, and Stn. 99, about 150 fathoms (V.U.W. Zoo. Dept.), 6/2/55, 23/2/56, 28/8/57, and 29/8/57, 568, 583, 670, 669; from the nest of a King Shag, on White Rock, Cook Strait (K. A. Wodzicki) 27/7/50, 195; off Mt. Benmore, middle ground, Cape Campbell, 30-50 fathoms (J. A. F. Garrick), 6/3/52, 287; Queen Charlotte Sound, South Island (Robert Baxter), 5/6/60, 738; off Otago Heads (Waitaki), 40 fathoms (E. J. Batham) 30/1/51, 68; Otago, Canyon A, “Alert” 54-13, 275-300 fathoms (E. J. Batham), 2/3/54, 610; Otago, Canyon A, “Alert” 55-5, 250 fathoms (E. J. Batham) 14/8/55, 611; Otago, Canyon E, “Alert” Stn. 54-9, 250-280 fathoms (E. J. Batham), 16/1/54, 512; oyster beds, Foveaux Strait (Canterbury Museum), -/9/37, 46.

Distribution. South Africa; New Zealand; Australia.

The tallest stem of N. cymodocea in the present collection comes from Queen Charlotte Sound. It is 35.0 cm in height and has a branch spread of 30.0 cm. The arrangement of the hydrocladia in the monosiphonic regions of stem and branches is just as described by Ritchie (1907) for “Antennularia hartlaubi”.

Pycnotheca Stechow, 1919

Hydrocladia bearing hydrothecae arising from athecate erect main stem; hydrotheca with well developed abcauline intrathecal ridge so that there is a secondary theca external to the true thecal cavity; no lateral nematothecae associated with the hydrotheca; a prominent tubular mamelon in the axil of each hydrocladium; mesial nematothecae below hydrotheca fixed, not moveable.

Pycnotheca mirabilis (Allman, 1883) var. mirabilis. Fig. 7, a-b

1883. Diplocheilus mirabilis Allman, p. 49, PI. VIII, figs. 4-7. 1894. Kirchenpaueria mirabilis (Allman). Bale, 109, PI. VI, figs. 4-7. 1919. Pycnotheca mirabilis (Allman). Stechow, p. 110. 1930. Pycnotheca mirabilis (Allman). Totton, p. 216, text-fig. 55, a-d (synonymy). 1950. ? Kirchenpaueria mirabilis (Allman). Hodgson, p. 50, figs. 81, 82. 1958. Pycnotheca mirabilis (Allman). Millard, p. 213.

A species with sparingly branched stem of medium height, up to 8.0 cm; stem monosiphonic, or with a few accessory tubes; hydrocladia regularly alternate arising from the distal end of the internode; basal two or three stem internodes without a branch; basal two or three nodes transverse, nodes elsewhere on the stem, and branches oblique; stem internodes often irregular in occurrence; stem intemodes from 0.60 to 2.75 mm in length and 0.30 to 0.40 mm in width; stem apophysis carrying hydrocladia with a distinct “ mamelon ” on postero-superior side; nodes regularly divide the hydrocladia into thecate internodes; hydrocladia with from approximately six to eight hydrothecae; internodes of the hydrocladia

0.35 to 0.55 mm in length and 0.13 to 0.25 mm in width; hydrothecae longer than wide; approximately one-third of the adcauline wall free from the internode; proximal region of fixed adcauline wall almost parallel to the internode axis, distal region and free adcauline wall bending outwards; aperture oblique, more or less circular, with a smooth margin; abcauline wall immediately below the margin with very well developed intrathecal ridge which extends approximately half-way across the theca; base of hydrotheca rounded when viewed laterally; length of abcauline wall of hydro theca 0.20 to 0.22 mm; maximum width of hydrotheca at margin approximately 0.25 mm; nematothecae —mesial nematotheca fixed, erect, aperture facing upwards (vertically, towards the hydrotheca); distal chamber broad, shallow, and with little or no adcauline wall; length of mesial nematothecae approximately 0.07 mm; mesial nematothecae found below each hydrotheca; stem nematothecae, simple, scoop- or cowl-shaped, at the distal end of each internode, and one on the antero-superior side of the apophysis opposite the “ mamelon ”: gonotheca, found towards the base of the stem, one gonotheca per internode, tapering proximally, rounded but somewhat truncated distally; walls with irregular, wide, transverse undulations; aperture lacking operculum or marginal rings; length of gonothecae up to 1.60 mm and 0.85 mm in maximum width.

Locality. Type locality, Moncoeur Island, Bass Strait, 30-40 fathoms (Allman, 1883): near North Cape, Stn. 134 “Terra Nova”, 11-20 fathoms; off Three Kings Islands, Stn. 90, “Terra Nova”, 100 fathoms; off Cape Maria van Diemen, Stn. 144, “Terra Nova”, 35-40 fathoms (Totton, 1930).

Distribution. New Zealand; Australia; Tasmania; South Africa.

This species is not represented in the present collection, and the above description of the erect stem is from British Museum (Natural History) material. The Tasmanian material described by Hodgson (1950, p. 50, figs. 81, 82) as “ Kirchenpaueria” mirabilis, has hydrothecae in which the width is the same, or greater than the depth (width, 0.30-0.33 mm; depth, 0.28-0.33 mm); the abcauline intrathecal ridge relatively narrow, and the opening of the mesial nematothecae horizontal, rather than vertical (cf. fig. 81, Hodgson, 1950). All these characteristics demonstrate a closer similarity to Pycnotheca producta, as described and figured by Totton (1930), than to P. mirabilis. Perhaps Hodgson’s Tasmanian material is a new varietal form of P. producta.

The following species Halicornopsis elegans (Lamarck) was described from New Zealand waters as early as 1873, but not recognized as such, by Hutton, who described it as Plumularia banksii Gray, 1843. It was shown by Coughtrey that Hutton’s “P. banksii” was not the P. banksii of Gray and Coughtrey, who regarded it as a new species, describing it first (1875) as Plumularia huttoni and later (1876, a) as Aglaophenia huttoni. However, Kirchenpauer (1876) had shown that Hutton’s Plumularia pennatula was not the P. pennatula of Ellis and Solander, and renamed this species also as Aglaophenia huttoni. Both A. huttoni (Coughtrey) and A. huttoni Kirchenpauer came from Lyall Bay, Wellington, and were regarded by Bale (1924) as an indeterminable species. Material has now become available that determines A. huttoni (Coughtrey) as Halicornopsis elegans (Lamarck) and A. huttoni Kirchenpauer as Halicornaria longirostris Kirchenpauer.

Among the material kindly loaned me by Canterbury Museum, Christchurch, was a box of microslides labelled “ Hutton’s types ”, and there is little or no doubt that all the slides in the box were Hutton’s and that many of them were the specimens he described in 1873. In this latter category is a microslide of material from Wellington, with a label that appears originally to have read Plumularia huttoni Coughtrey, The Plumularia has been crossed through and below it Aglaophenia has been written. This microslide shows a small portion of an infertile stem of Halicornopsis elegans. Confirmation that this slide was made from material used by Hutton to describe his “ Plumularia hanksii ” (later A. huttoni, now H. elegans) comes from a specimen labelled simply ec Plumularia banksii ”, in the hydroid material kindly loaned me by the Otago Museum, Dunedin. This specimen is also readily recognizable as Halicornopsis elegans. Furthermore, Hutton described the stems of “P. hanksii ” as polysiphonic. This erect stem

habit is characteristic of the taller stems of H. elegant. (The type of material of Aglaophenia huttoni Coughtrey is now Canterbury Museum slide No. 53.) Halicornopsis elegant is not represented in the present collection, and the material taken by Hutton from Wellington is the only record of the species from New Zealand. H. elegant is, however, well known from Australian waters.

Halicornopsis Bale, 1882

Erect stem with athecate main stem carrying the hydrothecate hydrocladia; hydrothecae with a well developed abcauline intrathecal ridge so that there is a secondary theca external to the true thecal cavity; abcauline wall of secondary theca containing three diverticula from the true hydrothecal cavity; a tubular “ mamelon ” in the axis of each hydrocladium; no lateral nematothecae associated with the hydrotheca; mesial nematotheca below the hydrotheca fixed, not moveable.

Halicornopsis elegans (Lamarck, 1816) Fig. 7, c-e.

1816. Plumularia elegans Lamarck. 1816. Aglaophenia elegans Lamouroux, p. 169. 1872. Aglaophenia avicularis Kirchenpauer, p. 27, p. 33, PI. I; PI. 111, fig. 3. 1873. Plumularia banksii of Hutton, p. 259, not P. banksii of Gray, p. 294. 1875. Plumularia banksii of Coughtrey, p. 289, not of Gray. 1876. Plumularia huttoni Coughtrey, p. 290. 1876 a. Aglaophenia huttoni (Coughtrey). Coughtrey, p. 31. 1882. Halicornopsis avicularis (Kirchenpauer) Bale, p. 185, PI. X, figs. 1 and 2; PI. XIX, fig. 32. 1883. Azygoplon rostratum Allman, p. 54, PI. XIX, figs. 1-3. 1887. Aglaophenia banksii of Bale, p. 103. 1930. Halicornopsis elegans (Lamarck). Totton, p. 214, Text-fig. 54, a and b. 1950. Halicornopsis elegans (Lamarck). Hodgson, p. 48, fig. 79 (synonymy).

A tall species up to 15.0 cm in height, and with distinctive hydro thecae bearing three large, sharply pointed marginal teeth, one on each side of the cup, and a median abcauline tooth; erect stems irregularly branched and taller stems with both the lower stem and branches polysiphonic, but upper stem and branches monosiphonic; hydrocladia alternate, close together and one or two per stem internode; nodes on the stem, branches and hydrocladia, oblique; stem internodes approximately 1.25 mm in length and 0.37 mm in width; stem apophysis with a distinct tubular “ mamelon ” on the postero-superior side; apophysis approximately 0.40 mm in length; nodes regularly divide the hydrocladia into thecate internodes; hydrocladia usually with twelve or more hydrothecae; internodes of hydrocladia 0.28 to 0.40 mm in length and 0.15 to 0.40 mm in width; hydrotheca set at an angle of approximately 45° to the axis of the internode; hydro theca shallow, about as deep as it is wide; marginal teeth three in number, two lateral teeth pointing outwards and a very large, sharply pointed median adcauline tooth (rostral tooth) with a slight upward curve; inner side of rostral tooth projecting into the hydrotheca forming an intrathecal ridge; intrathecal ridge divides the hydrotheca into a lower cavity, the true hydrothecal cavity and an upper secondary cavity; diverticula extend from the true hydrothecal cavity into all the marginal teeth; very little of the adcauline wall of the hydrotheca free from the internode; base of the hydrotheca rounded, when viewed laterally; length of the abcauline wall of the hydrotheca excluding rostral tooth, 0.150 to 0.225 mm; maximum width of hydrotheca at the margin approximately 0.22 mm when viewed laterally; maximum width of hydrotheca when viewed in frontal aspect approximately 0.37 mm; length of rostral tooth approximately 0.20 mm; the mesial nematotheca situated on the abcauline side of the hydrotheca at the base of the rostral tooth, is short, scoop-shaped, and open on the inner side; other small scoop-shaped nematothecae present on the stem and branches above the origin of the hydrocladia, one on the base of the hydrocladium and one in the axil; a small nematopore present between the hydrocladial internode and the adcauline wall of the hydrotheca, the opening of which is either protected by a delicate flap of perisarc, or unprotected; mesial nematothecae 0.10 to 0.14 mm in length; gonotheca irregularly ovate, thick-walled, carried on the apophysis at the base of the hydrocladium; aperture and operculum not readily observed.

Locality. Type locality, Indian Ocean (cf. Lamouroux, 1816); Lyall Bay, Wellington, (Hutton, 1873 as Plumularia banksii ).

Distribution. Indian Ocean; Australia; Tasmania; New Zealand.

The above description of H. elegant was compiled from several sources —viz.,

from Hutton’s specimen of “ P.” hanksii from Totton’s (1930) and Hodgson’s (1950) description, and from material of Azygoplon rostratum Allman, The measurements were all taken from the monosiphonic region of the erect stem.

Subfamily Aglaopheniinae Stechow, 1911

Species of only one-third of the generally recognized genera of this subfamily are known from New Zealand waters —namely, species of the genera Halicornaria, Thecocarpus, Monoserius, and Aglaophenia. Species of the genera Nematocarpus, Lytocarpus, Aglaria, Aglaophenopsis, Dinotheca, Cladocarpus, Streptocaulus and Pentandra are not at present known from our waters. While some of the latter genera at present unknown from New Zealand are known from Australian seas the largest percentage of aglaopheninid species found in Australia belong, as in New Zealand, to the three genera Aglaophenia, Thecocarpus and Halicornaria.

Halicornaria Busk, 1852

Erect stems rooted by filiform stolons; often branched, hydrocladia pinnately arranged; margin of hydrotheca usually with teeth or lobes, and margin of hydropore usually with tiny needle-like chitinous projections; associated with each hydro theca a single mesial anterior nematotheca and two lateral nematothecae flanking the hydrotheca; lateral nematothecae often pear-shaped; no other nematothecae on the hydrocladia other than those associated with the hydrotheca; gonosome surrounded by a simple gonotheca, not protected by accessory structures; gonothecae arising from the main stem, or hydrocladia.

Only one species, Hahcornaria regalis Totton, 1930, has been recognized previously from New Zealand waters. It is now established that the specimen briefly described by Hutton in 1873 as Plumularia pennatula is Halicornaria longirostris (Kirchenpauer, 1872). Both H. regalis and H. longirostris are rare species round our coast, and each is recorded from a single North Island locality. H. regalis is an endemic species, but H. longirostris is well known in Australian seas.

Key to the New Zealand Species of Halicornaria

1 (2) Length of the internode to the width as 2:1; mesial nematotheca narrow, tubular, very long, its total length approximately twice that of the hydrotheca, adnate to the hydrotheca as far as the anterior marginal tooth, then produced sharply outwards and upwards, the distal upwardly directed portion being almost parallel to the axis of the internode H. longirostris (Kirchenpauer, 1872)

2 (1) Length of the internode to the width as 3:1; mesial nematotheca narrow, tubular, very long, its total length approximately twice that of the hydrotheca; adnate to the hydrotheca as far as the anterior tooth and then produced upward in a smoth curve H. regalis Totton, 1930

Halicornaria longirostris (Kirchenpauer, 1872) Fig. 7, h-i.

1872. Aglaophenia longirostris Kirchenpauer, p. 28, PI. I, fig. 19; PI. V, fig. 20. 1873. Plumularia pennatula of Hutton, p. 258, not of Ellis and Solander. 1875. Plumularia pennatula of Hutton. Coughtrey, p. 289, PL XX, fig. 37. 1876 a. Aglaophenia pennatula Coughtrey, p. 31. 1876. Aglaophenia huttoni Kirchenpauer, p. 24. 1884. Halicornaria longirostris (Kirchenpauer). Bale, p. 181, PI. XIII, fig. 3; PI. XIX, fig. 30 (synonymy).

1921. Aglaophenia zelandica nom. nov. for A. huttoni Kirchenpauer. Stechow, p. 260. 1924. Aglaophenia huttoni Kirchenpauer. Bale, p. 257 (synonymy of A. huttoni Kirchenpauer).

1942. Gymnangium longirostre (Kirchenpauer). Blackburn, p. 109 (synonymy). 1950. Halicornaria longirostris (Kirchenpauer), Hodgson, p. 51, fig. 83 (synonymy).

Erect stem of medium height, up to 9.0 cm in height; branched, with the branches in one plane; hydrocladia close together, alternate to sub-alternate, one or two to a stem or branch internode and arising from the proximal end of the internode; nodes oblique; stem internodes from 0.35 to 0.40 mm in length and 0.30 to 0.35 mm in width; stem apophysis bearing hydrocladia from 0.15 to 0.175 mm in length; nodes regularly dividing the hydrocladia into thecate internodes; hydrocladia with 14 or more hydro thecae; internodes of hydrocladia from 0.20 to 0.25 mm in length and 0.12 to 0.15 mm in width measured at the node; hydrotheca, deep, cup-shaped, at an angle of approximately 45° to the axis of the internode; anterior median tooth spine-like and curved inwards, a broad, shallow, rounded lobe behind and three lateral pairs of teeth, the first and second teeth of the paired laterals larger, and more widely separated than the other teeth; hydropore with tiny needle-like spines on the margin; no intrathecal ridges and no septal ridges across the internodes; length of abcauline wall of hydrotheca 0.16 to 0.18 mm; width of hydro theca approximately 0.15 mm at the margin and viewed laterally; nematothecae, mesial nematotheca, narrow, tubular, arising from the hydrocladium, fixed to the hydrotheca as far as the margin of the latter then curving abruptly outwards and then upwards almost parallel to the long axis of the internode; terminal and lateral apertures of mesial nematotheca readily recognizable, widely separated 0.15 to 0.20 mm apart; lateral nematothecae flanking hydrotheca small in comparison with mesial nematotheca approximately 0.09 mm in length, somewhat pear-shaped, lateral and terminal apertures very close together and may be confluent; nematothecae on the stem similar in shape to the lateral hydrothecal nematothecae, disposed one behind each hydrocladium, and two on the front of the stem internode: gonothecae, small, delicate, truncated at the distal end, and arising from the base of the hydrocladium and may form a single row for the greater part of the stem length.

Locality. Type locality, Wilson’s Promontory, Victoria, Australia (Kirchenpauer, 1872): Lyall Bay, Wellington (Hutton, 1873, as Plumularia pennatula).

Distribution. Australia, New Zealand.

As noted under Halicornopsis elegans, the loan of microslides from Canterbury Museum has made it possible to give a decision on species described by Hutton (1873), and previously thought to be indeterminable. One of these species was Plumularia pennatula of Hutton (not of Ellis and Solander) later recognized as Aglaophenia huttoni Kirchenpauer, 1876. A re-examination of Hutton’s microslide leaves no doubt that “P. pennatula ” is Halicornaria longirostris (Kirchenpauer). Bale (1924) thought it very probable from Hutton’s description of the erect stem, that the latter’s material from Wellington, New Zealand was H. longirostris. Bale hesitated, however, to place P. pennatula as a synonym of H. longirostris, because Hutton described the gonosome as a corbula, a type of gonosome not known for species of Halicornaria. The microslide in the Canterbury Museum collection is of a portion of an infertile stem, and from Coughtrey’s (1876) remarks, neither he, nor Hutton, had seen the gonosome of the material the latter regarded as P. pennatula Ellis and Solander. A possible explanation is that Hutton, believing his specimens to be P. pennatula, and wishing to give as complete a description as possible, quoted another author’s desciption of the gonosome and somehow quotation marks were omitted in the published work. If the Canterbury Museum slide had been available for Bale to examine in 1924 it is very unlikely, even in ihe absence of the gonosome, that he would have hesitated to recognize Hutton’s material of P. pennatula as H. longirostris because the long, upturned, mesial nematotheca of the hydro theca is distinctive, making specimens readily identifiable as the latter species.

Hutton’s is the only record of H. longirostris for New Zealand. The species is well known from South-Eastern, South Australian, and from Tasmanian waters.

Halicornaria regalis Totton, 1930. Fig. 7, f-g.

1930, Halicornaria regalis Totton, p. 241, text-fig. 70.

Species described from a detached branch 2.0 cm in length; hydrocladia alternate, as known one to each internode, and arising from the proximal half of the internode; nodes transverse; branch internodes approximately 0.43 mm in length and 0.25 mm in diameter; nodes regularly dividing the hydrocladia into hydrothecate internodes; hydrocladia with up to 15 hydrothecae, and up to 6.3 mm in length; internodes of hydrocladia from approximately 0.40 mm in length and 0.07 to 0.10 mm in width; hydrotheca greater in length than in width viewed laterally, set at an angle of 40° to 50° to the axis of the internode; anterior median

marginal tooth very small, scarcely visible in lateral view; three lateral pairs of teeth simple, and broadly pointed; the second lateral tooth everted; between the third lateral tooth and the internode is a rounded notch; hydropore with needle-like spines on the margin; no intrathecal ridge, and no septal ridges across the internode; length of abcauline wall of hydrotheca 0.22 to 0.30 mm; width of hydrotheca at the mouth viewed laterally, approximately 0.17 mm, and viewed from the front 0.25 mm; nematothecae —mesial nematotheca, narrow, tubular, arising from the hydrocladium, fixed to the hydrotheca as far as the margin, then produced outwards at almost the same angle but with a slight upward curve, as the abcauline wall; terminal and lateral apertures of mesial nematotheca easily observed, widely separated approximately 0.20 mm apart; lateral nematotheca flanking the hydrotheca small in comparison with the median nematotheca, somewhat pear-shaped (Fig. 7, f) fixed to the internode, lateral and terminal apertures confluent so that inner free portion gutter-shaped; nematothecae on the branch similar in shape to the lateral nematothecae flanking the hydrotheca, disposed one behind each hydrocladium and two on the front of the branch internode: gonotheca, carried on a pedicel, truncated at the distal end, subcylindrical, longer than broad; a single gonotheca arising from the anterior surface of the branch apophysis; sporosac enclosed in a fine chitinous membrane; gonotheca 0.55 to 0.70 mm in length excluding the pedicel; and 0.32 mm in maximum width.

Locality, Type locality, off Three Kings Islands, New Zealand, 100 fathoms (Totton, 1930), Species known only from the type locality.

H. regalis is not represented in the present collection. As described by Totton (1930), the species is “ allied to H. humilis, Bale, and to H. polifera. Bale ”, and to //. africana Millard, 1958 (Millard, 1958). It differs from H. humilis in that the mesial nematotheca of H. regalis is adnate to the hydrotheca for a greater length than it is in H. humilis and the anterior tooth of H. regalis is smaller than that of H. humilis : from H. prolifer ain possessing smaller nematothecae flanking the hydrotheca, narrower and straighter mesial nematotheca, hydrothecae more widely separated and with less strongly everted marginal teeth and a smaller anterior tooth: from H. africana in having the hydrothecae more widely separated, the intemode being longer in relation to the width than that of H. africana, and in having a smaller anterior marginal tooth and the first lateral tooth the smallest of the three.

The third lateral tooth is the smallest in H. africana.

Re-examination of material of H. regalis shows that the lateral marginal teeth are variable in size and that the third is not always the largest. Sometimes, the first lateral is the largest as in A. africana and at others, all the lateral teeth are of approximately equal size. Nonetheless, the very different length-breadth ratio of the internode of H. regalis to that of H. africana and the smaller anterior tooth readily identifies H. regalis as at present known.

Monoserius Marktanner-Turneretscher, 1890

Erect stems usually rooted by filiform stolons; stems may or may not be branched; hydrocladia pinnately arranged; margin of hydrotheca usually with teeth; associated with each hydrotheca on the non-specialized hydrocladia, is a median anterior nematotheca and a lateral nematotheca on each side flanking the hydrotheca: gonosome protected by accessory structures; the secondary hydrocladia arranged in one row on one side only of the primary hydrocladia.

Bale (1924) recognized Gray’s Plumularia banksii as a species of Hemicarpus Billard, 1913. More recently, however, Leloup (1932) demonstrated that the genus Hemicarpus was a synonym of Mono serins Marktanner-Turneretscher, 1890, and Gray’s material is descibed here as a species of the latter genus. The species is not represented in the present collection and the description below is based on that of Bale (1924) and the measurements calculated from his Figure 17, a.

Monoserius banksii (Gray, 1843). Fig. 8, h.

1843. Plumularia banksii Gray, p. 294. 1887. Aglaophenia banksii (Gray). Bale, p. 103. 1924. Hemicarpus banksi (Gray). Bale, p. 263, fig. 17, a (synonymy).

Erect stem polysiphonic and branched; hydrocladia alternate, directed towards the front, and from 5.0 to 8.0 mm apart; nodes on hydrocladia slightly oblique and dividing the hydrocladia regularly into thecate internodes; internodes of hydrocladia approximately 0.21 mm

in length and 0.15 mm in width; a narrow thickening in the internode opposite the intrathecal ridge of the hydrotheca; hydrotheca subconical, narrowing between the mesial nematotheca and the margin, with a small intrathecal ridge on the adcauline side near the base; a small curved or sigmoid shaped, sharply defined intrathecal fold projecting from the intrathecal ridge about a third of the way across the hydro theca; sides of the hydro theca more prominent than either the front or the back of the hydrotheca; hydrothecal margin with small, uneven undulations, those on the two sides not corresponding; a well developed, conspicuous, incurved, anterior median marginal tooth; all of the adcauline wall of the hydrotheca fixed to the internode; nematotheca —mesial nematotheca shorter than the hydrotheca, fixed to the hydrotheca for slightly more than half the adcauline length, a small orifice connecting the cavity of the hydrotheca with that of the mesial nematotheca; free portion of the mesial nematotheca projecting outwards from the hydro theca, widely open in front, and the sides forming a wide angular lobe; length of mesial nematotheca viewed laterally, approximately 0.15 mm; lateral nematothecae flanking the hydrotheca, short, and very wide, with the whole front margin free; lateral nematotheca approximately 0.06 mm in length viewed laterally: gonosome unknown.

Locality. “New Zealand” (Gray, 1843). Species known only from one New Zealand record.

Thecocarpus Nutting, 1900

Erect stems usually rooted by filiform stolons; stems may, or may not be branched; hydrocladia pinnately arranged; margin of hydrotheca usually with teeth, or lobes; margin of hydropore usually lacking, tiny needle-like projections; associated with each hydrotheca, on the non-specialized hydrocladia, is a median anterior nematotheca and a lateral nematotheca on each side flanking the hydrotheca; lateral nematothecae frequently tubuliform; no other nematothecae on non-specialized hydrocladia other than those associated with the hydrotheca: gonosome protected by accessory structures; accessory structures forming a corbula; secondary hydrocladium I (gonohydrocladium) with a hydrotheca at the base.

Four species of Thecocarpus have been described previously from New Zealand—namely, T. ctenatus Totton, 1930; T. rostratus (Bale, 1924) ; T. chiltoni Bale, 1924; and T. spiralis Totton, 1930. A new species, T. sub dichotomies, from the Chatham Rise is described here.

One change of name is necessitated by the finding of the type specimen of Plumularia incisa Cough trey, 1875, a species previously thought to be “ indeterminable Thecocarpus rostratus (Bale, 1924) is shown to be a synonym of Coughtrey’s species incisa. Bale (1924) foresaw the possibility of this decision. Also, a name change seems to be indicated for T. ctenatus , Totton. Totton (1930) describes the open corbula of this species as possessing “ seventeen pairs of short gonohydroclades without theca ”, and species in which the gonohydroclade lacks a theca are now generally recognized as species of the genus Aglaophenia. Accordingly T. ctenatus is described here as Aglaophenia ctenata.

As at present known, T. subdichotomus, from the offshore Chatham Rise area, is the only species of this genus occurring southward of Cook Stait, All the New Zealand species of Thecocarpus, except T. subdichotomus, are known from far northern waters in the Three Kings Islands and Cape Maria van Diemen area; all, including T. subdichotomus, have been taken either by dredging or from storm drift, suggesting that their depth range is predominantly sublittoal, and all are endemic species. T. incisus is the commonest species of Thecocarpus round our coast and has been taken from east and west coast North Island waters and ranges from Gape Maria van Diemen to Cook Strait.

Key to the New Zealand Species of Thecocarpus

1 (2) Mesial nematotheca reaches approximately the margin of the hydrotheca: median hydrothecal tooth with a very large sharply pointed forwardly directed rostral spine which usually extends beyond the mesial nematotheca T. incisus (Coughtrey, 1875)

2 (1) Mesial nematothecae short, ending well below the margin of the hydrotheca.

3 (4) Hydro theca very deep, narrow and cylindrical; parallel with the long axis of the internode; with seven small, lateral pairs of marginal teeth ...... ...... T. spiralis Totton, 1930

4 (3) Hydrotheca deep, but not narrow and cylindrical, widest at the aperture, parallel with the long axis of the internode, with less than seven small lateral pairs of marginal teeth.

5 (6) Hydrotheca with prominent anterior median marginal tooth which bears a small erect spinous crest; nematothecae with gutter-like apertures; four pairs of lateral marginal teeth T. chiltoni Bale, 1924

6 (5) Hydro theca with small, sharply pointed median marginal tooth lacking a spinous crest; nematothecae with circular terminal opening, clearly separate from the lateral aperture; five pairs of lateral marginal teeth T. subdichotomus n.sp.

Thecocarpus incisus (Coughtrey, 1875). Fig. 8, c-g,

1875. Plumularia incisa Coughtrey, p. 290, PI. XX, figs. 40 and 41. 1876 a. Aglaophenia incisa (Coughtrey). Coughtrey, p. 31. 1924. Halicornaria rostrata Bale, p. 264, fig. 18. 1928. Thecocarpus formosus (Busk) var. inarmatus Trebilcock, p. 26, PI. V, fig. 6; (not Plumularia formosa Busk, 1851). 1930. Thecocarpus rostratus (Bale). Totton, p. 237, Text-fig. 69, b.

Erect stems of medium height up to 11.5 cm in length; stems growing in tufts from tangled hydrothizae, or growing from hydrorhizal stolons creeping over sponges and other organisms; stems monosiphonic, unbranched, except for the hydrocladia and occasional abnormal regenerations; five to six millimetres at base of stem lacking hydrocladia, the proximal region of which is smooth without nodes, the distal region with five or six nodes, and internodes each with a double mesial nematotheca; hydrocladial region of stem with approximately twelve hydrocladia per side in each centimeter of stem; hydrocladia approximately 1.0 cm in length; hydrocladia alternate, one per internode set at an angle of about 45°, both series directed forward; hydrocladial nodes slightly oblique, dividing the hydrocladium regularly into thecate internodes; stem internodes from 0.20 to 0.40 mm in length and 0.15 to 0.21 mm in width; stem apophysis approximately 0.10 mm in length; internodes of hydrocladia from 0.19 to 0.35 mm in length and 0.09 to 0.12 mm in width; hydrothecae at an angle of about 40° very narrow at the base and widening towards the aperture; a narrow, small, intrathecal ridge on the adcauline side near the base; front of hydrotheca produced into a very large hollow, pointed prominence (rostral spine) at the base of the prominent anterior tooth; rostral spine in free communication with the cavity of the hydrotheca; rostral spine shorter on the proximal hydrothecae of the hydrocladium than on the distal hydrothecae; rostral spine from 0.10 to 0.25 mm in length; four pairs of lateral pointed teeth, the first and third everted, the fourth reduced especially on hydrothecae at the distal end of the hydrocladium; first and second laterals single, not double as in T. formosus; a small ridge in the internode at approximately the level of the adcauline intrathecal ridge; all of the length of the adcauline wall of the hydro theca fixed to the internode; length of the abcauline wall of the hydrotheca approximately 0.25 mm; width of hydrotheca at margin, viewed laterally 0.15 to 0.16 mm; nematothecae—mesial nematotheca from 0.17 to 0.25 mm in total length, fixed to the hydrotheca for more than half the abcauline length of the hydrotheca, free part slightly recurved towards the distal tip which reaches almost to the margin of the hydrotheca; free portion of nematotheca with large gutter-shaped opening; lateral nematothecae 0.10 to 0.12 mm in length, flanking the hydrotheca and fixed to the hydrotheca to the level of the hydrothecal margin, then directed outwards; lateral nematothecae alongside distal hydrothecae larger than those flanking proximal hydrothecae on hydrocladium; stem internodes have two nematothecae at the base of each hydrocladium, one in front and one behind each axil; gonosome—borne on a modified hydrocladium which forms a protective corbula; corbula closed, approximately 3.50 mm long, including the basal peduncle which carries a single hydro thecate internode; internodes of the rachis short, 0.15 to 0.175 mm in length, carrying three series of modified hydrocladia, the gonohydrocladia (secondary hydrocladia I) the costae (secondary hydrocladia II) and the costal apophyses (secondary hydrocladia III); at the base of each type of branch are usually three nematothecae although the lateral may be absent in the distal region of the corbula; the gonohydrocladia form prominent spurs approximately 0.30 mm in length, bear one basal hydro theca about which are disposed the three usual nematothecae as seen on the non-specialized hydrocladia, and in addition a

mesial nematotheca above the cup; hydrothecae on gonohydrocladia usually with poorly developed marginal teeth and the anterior tooth lacks the rostral spine; the costae or corbula leaflets number 8 to 12 pairs and grow out from between the hydrotheca and the mesial infrathecal nematotheca and carry on their distal edge from 8 to 12 closely set large tubular nematothecae; the costal apophysis is small and sub-triangular and arises from the base of the distal edge of the costa distal to it.

Specimens of T. incisus dredged in Cook Strait have usually long rostral spines on the anterior tooth of the hydrotheca (Fig. 8, e) and the distal edge of the costal leaflets in the corbula show the nematothecae carried on the inner face of narrow, long, tubular structures that arch over the broad leaf-like region of the costa. It seems likely that male and female stems can be distinguished in T. incisus and differ in the characters noted above. The reproductive zooids in the present material are not sufficiently mature to determine which are male and which female corbulae.

Hutton placed at Coughtrey’s disposal his type collection and lent the latter other specimens he had collected (c.f. Coughtrey, 1875, p. 281). One specimen collected by Hutton from Lyall Bay, Wellington, was described by Coughtrey (1875) as a new species Plumularia incisa. Later (1876 a) Coughtrey renamed the latter species Aglaophenia incisa. Coughtrey’s description of A. incisa was brief and his figures inadequate for identification and the species was regarded by Bale (1924) as indeterminable but possibly similar to his new species Halicornaria rostrata. It can now be shown that Aglaophenia incisa and Halicornaria rostrata are one and the same species. The type microslide of " Plumularia ” incisa was among others in a box labelled “ Hutton’s types ”, kindly loaned me by Canterbury Museum, Christchurch, and the distinctive “ rostrum ” projecting from the base of the anterior tooth identifies “ P. M incisa with Halicornaria rostrata Bale, 1924. A microslide of the latter species is also in the Canterbury Museum collection. Accordingly H. rostrata is now recognized as a synonym of “ P.” incisa. However, the corbulae found on many of the present specimens show that “ P.” incisa is a species of Thecocarpus. Totton (1930) also regarded Bale’s Halicornaria rostrata as a species of Thecocarpus presumably because of the general similarity of its hydrothecae to those of T. formosus (Busk). The gonosome is described here and the structure of the gonohydrocladium (secondary hydrocladium I), is that shown by species of the genus Thecocarpus. Totton (1930) also recognized Trebilcock’s var. inarmatus of Thecocarpus formosus as Thecocarpus rostratus (now T. incisa) and the present material indicates that Totton was correct in his identification of Trebilcock’s material as T. “ rostratus ”.

The present material also shows that the rostral spine is more variable both in length and width than was previously known (Fig. 8, d, e and g), and that in a few instances (Fig. 8, e) reaches a length comparable to that of T. formosus. Also, in mounted specimens of T. incisus, the strongly everted first and third teeth often become folded over giving the appearance of a double tooth such as that found in the first and second laterals of T. formosus. Nonetheless, the characters used by Totton (1930) to distinguish his specimens of “ rostratus” from T. formosus hold also for the present material. The hydrocladia of T. incisus are longer than those of T. formosus, the hydrocladia lack the terminal spine present in T. formosus, the first and second lateral teeth in T. incisus are single, not double as in T. formosus, and the rostral spine with rare exceptions is much shorter in T. incisus than in T. formosus.

Bale (1924) notes that Allman recorded T. formosus from New Zealand and Australia. Bale did not find T. formosus among the extensive collections of Australasian material that he examined, and Vervoort (1946) and the present author are unable to verify Bale’s note concerning Allman’s record of the species from Australasia. All in all, the record of T. formosus from New Zealand must be regarded as very doubtful.

Thecocarpus spiralis Tot ton, 1930. Figs. 8, i-j; 10, d. 1930. Thecocarpus spiralis Totton, p. 238, Text-fig. 69, c-d. A very distinctive New Zealand species of Thecocarpus with very deep, elongate, almost

cylindrical hydrothecae and short mesial nematotheca; erect stem of medium height up to 16.0 cm , polysiphonic, with a basal diameter of from 2.0 to 3.0 mm; base of stem for approximately three to four centimeters without branches; medial and proximal stem giving rise to branches 3.0 to 4.0 cm in length that are arranged in a loose spiral, six branches to each complete turn; all branches originating from the main stem, not the accessory tubes; secondary communications between the stem and the accessory tubes; hydrocladia approximately 1.5 mm apart, up to 14.0 mm in length; nodes transverse, dividing the hydrocladia regularly into thecate internodes; approximately twelve hydrothecate internodes to a centimetre; length of hydrocladial internode 0.80 to 0.90 ram, and width of hydrocladia 0.10 to 0.15 mm; hydrotheca elongate, cylindrical, almost parallel to the long axis of the internode, and aperture almost at right angles to internode; margin with small but readily recognizable sharply pointed median anterior tooth and seven pairs of low, pointed, lateral teeth; a small but distinct intrathecal ridge very near the base of the hydro theca; abcauline wall of hydro theca 0,70 to 0.75 mm in length and hydrotheca 0.20 to 0.25 mm in width at the margin viewed laterally; hydrocladial internodes with two or three septal ridges, one approximately at the level of the paired lateral nematothecae of the hydrotheca, another about mid-way in the adcauline length of the hydrotheca and one other opposite the intrathecal ridge of the hydrotheca; nematothecae—mesial nematotheca at an angle of approximately 45° to the internode, fixed to the hydro theca for almost all its length, aperture an open canal; length of mesial nematotheca approximately 0.25 mm; paired lateral nematothecae flanking the hydrotheca tubiliform, fixed to the internode for nearly all their length, and not reaching the margin of the hydrotheca; aperture of lateral nematothecae an open canal similar to that of the mesial nematotheca; three nematothecae all with open gutter-like apertures at the base of each hydrocladium and a “ mamelon ” on the stem apophysis bearing the hydrocladium; branch internodes with three to four nematothecae in the front mid-line; gonosome, borne on a modified hydrocladium which forms a protective corbula; corbula closed, up to 10.0 mm including peduncle; corbula shows transition from the normal hydrocladial structure in the proximal region to a stem with the hydrocladia branched three times, lacking hydrothecae and forming a closed corbula in the distal region; in the intermediate region of the corbula the hydrocladia are simple, branched stems lacking an hydrotheca on the stem and with progressively reduced hydrothecae one on each of four secondary hydrocladia, the distal two of which each have a tertiary branch; the “ supernumery ” mesial nematotheca found on the main stem is present on some internodes of the corbula rachis; “each gonohydroclade or branch of the corbula rachis, apart from four proximal ones, which do not form part of the corbula, consists of a flat expansion—the “ lateral spur ”, representing the growing point of a hydroclade, and generally bears on its distal edge three nematothecae, as well as from one to five on the other; each lateral spur possesses three nematothecae but lacks hydrothecae, and gives rise to a branch to form the broad corbula leaflet (costa); nematothecae present on the distal edge of each leaflet; costal apophysis small, arising from the distal edge of the basal region of a secondary branch; costal apophysis surrounded by three nematothecae and fused with the proximal edge of the leaflet in front; fused distal ends of leaflets with small free expansions.”

Locality. Type locality, off Three Kings Islands, Stn. 90, “Terra Nova”, 100 fathoms (Totton, 1930): off Port Waikato, West Coast, North Island, 30 fathoms (H. J. Chapman) 13/9/56, 620. Species known only from New Zealand waters.

Among the specimens in the present collection from Port Waikato are some fertile stems. It was not possible, however, to observe all the features noted by Totton (1930) as the corbulae were in a poor state of preservation, but as far as could be ascertained these corbulae are similar to those described by Totton. The description above of the corbula of T. spiralis is based on Totton’s original account.

Thecocarpus chiltoni Bale, 1924. Fig. 8, a-b.

1924. Thecocarpus chiltoni Bale, p. 261, fig. 16. 1930. Thecocarpus chiltoni Bale. Totton, p. 240, Text-fig. 69, e.

Erect stem tall, up to 23.0 cm in height, arising from vertically elongated rooting masses of hydrorhizae; stem polysiphonic, up to 8.0 mm in diameter at the base; branched, branches in one plane, up to 7.5 cm in length, and may rebranch as many as four times; branches pinnately arranged, main branches about 1.0 cm apart; all branches arising from the main stem at about an angle of 45° and not from the accessory tubes; hydrocladia close together on branches, alternate, set at an angle of approximately 45°, one per internode and both series directed slightly towards the front; hydrocladia divided by transverse nodes regularly into thecate internodes; internodes of monosiphonic region of stem and branches 0.16 to 0.50 mm in length and approximately 0.20 mm in width; internodes of hydrocladia from 0.15 to 0.30 mm in length and 0.14 to 0.15 mm in width; hydrothecae at an angle of approximately 40° to the axis of the internode; hydrotheca deep, rather narrow at the base, widening gradually

to the margin; a narrow intrathecal ridge on the adcauline side of the hydrothecae near the base and with a distinct intrathecal fold arising from the ridge and curving slightly upward as it crosses the hydrothecal cavity to almost the abcauline wall; hydrothecal margin with well developed teeth, a prominent anterior tooth the front of which is produced into a spinous process and four teeth on each side, the first and fourth of which are thin, often difficult to see, and the second and third larger subtriangular, with rounded tip; all of the adcauline side of hydrothecae fixed to internode; internode with short septal ridges opposite the intrathecal ridge and the base of the lateral nematothecae; length of abcauline wall of hydrotheca 0.175 to 0.200 mm; width of hydrotheca at the margin, viewed laterally, 0.125 to 0.150 mm; nematothecae—mesial nematotheca 0.14 to 0.175 mm in length, a little shorter than the hydrotheca, fixed for all its length to the hydrotheca; aperture gutter-like, sloping outwards away from the hydrotheca; lateral nematothecae approximately 0.10 mm in length, flanking the hydrotheca, tubular, fixed to the hydrotheca almost to the level of the hydrothecal margin, and then free and projecting forwards; stem nematothecae, two at the base of each hydrocladium, the lower projecting forward, the upper larger and projecting outward, and one on the stem to one side of the lower nematotheca; gonosome, borne on a modified hydrocladium which forms a protective corbula; corbula closed, approximately 5.0 mm long, including the basal peduncle; the rachis (gonocladium) carries three kinds of branches, the gonohydrocladium (secondary hydrocladium I), the costa (secondary hydrocladium II), and the costal apophysis (secondary hydrocladium III); at the base of each type of branch are three nematothecae except in the distal region of the rachis where the laterals are absent, only the median infrathecal one remains; the gonohydrocladium bears one hydrotheca about which are disposed the three usual nematotheca as seen on nonspecialized hydrocladia, and in addition, a distal median nematotheca above the cup; the costa or corbula leaflet grows out from between the hydrotheca and the mesial infrathecal nematotheca, and carries on its distal edge from five to eight closely set, tubular nematothecae; the costal apophysis is small and subtriangular and arises from the base of the distal edge of the costa; each costal apophysis unites with the hinder edge of the base of the costa distal to it.

Locality. Type locality, off Cape Maria van Diemen, 10 miles north-west, 50 fathoms (Bale, 1924); off Three Kings Islands, Stn. 90, “Terra Nova”, 100 fathoms (Totton, 1930); off Gape Maria van Diemen, Stn. 144, “Terra Nova”, 40 fathoms (Totton, 1930); Gape Reinga, between Cape Maria van Diemen and North Gape, storm drift (W. H. Dawbin), 10/5/50, 34; Napier, foreshore, storm drift (P.M.R.), 19/11/50, 2. Species known only from New Zealand.

Thecocarpus subdichotomus n.sp. Figs. 9, c-e; 10, e.

Erect stem tall, up to 20.0 cm in height; not stiff, flexible, subdichotomously branched, polysiphonic, at the base of the stem and branches, becoming monosiphonic in the medial and distal regions of both stem and branches; stem arising from a cluster of hydrorhizal stolons; base of stem free of branches and hydrocladia for approximately 6.0 cm; stem apophyses and associated nematothecae readily observed on basal region of stem, suggesting that lower branches and hydrocladia are shed as growth in length proceeds; approximately seven alternating pairs of hydrocladia between each branch; branches up to 3.59 cm in length and with up to 30 alternating pairs of hydrocladia; hydrocladia arising from fronto-lateral aspect so that erect stem has a clearly defined front and back aspect; hydrocladia carried on a well developed apophysis, the latter approximately 0.125 mm in length; nodes oblique, readily observed in all regions of erect stem, and dividing the hydrocladia regularly into thecate internodes; internodes of stem and branches from 0.40 to 0.60 mm in length and 0.15 to 0.20 mm in width; hydrocladial internodes 0.40 to 0.45 mm in length and 0.12 to 0.15 mm in width measured at the node; hydrothecae deep, basal region distinctly bulbous; one well developed adcauline intrathecal ridge in the basal half of the hydrotheca; aperture of hydrotheca with an oblique downward slope; margin of hydrotheca with a sharply pointed median anterior tooth and five pairs of low but pointed lateral teeth, the fifth lateral tooth very sharply pointed and in lateral view often appearing as a tiny spike alongside the lateral nematotheca; abcauline length of hydrotheca from 0.25 to 0.31 mm; width of hydrotheca at the margin viewed laterally from 0.13 to 0.14 mm; nematothecae—mesial nematotheca approximately 0.20 mm in length, adnate to the hydrotheca for nearly all its length; free portion short, directed outwards from the hydrothecal wall; terminal aperture circular and close to, but distinct from the lateral aperture; a small opening between mesial nematotheca and cavity of hydrotheca; lateral nematothecae flanking hydrotheca from 0.095 to 0.12 mm in length, adnate to the hydrotheca up to the margin of the latter; short free portion turned outwards; terminal aperture circular approximately 0.01 mm in diameter, and close to, but distinct from, the lateral aperture; stem nematothecae one in the axil of the hydrocladium, one on the stem almost

alongside the axillary nematotheca and one on the proximal region of the internode; gonosome borne on a modified hydrocladium which forms a protective corbula; corbula closed, from 8.0 to 9.0 mm in length including the basal peduncle which carries from four to five hydrothecate internodes; margin of hydrothecae on peduncle with smaller, more rounded teeth than on non-specialized hydrocladia, and occasionally mesial nematotheca separate not adnate to the hydrotheca; apophysis of peduncle usually with a single mesial nematotheca; internodes of rachis short, approximately 0.20 mm in length, carrying three series of modified hydrocladia, the gonohydrocladia (secondary hydrocladia I), the costal “leaflets”, (secondary hydrocladia II), and the costal apophyses (secondary hydrocladia III); gonohydrocladia form very prominent spurs approximately 0.55 mm in length, bear one basal hydrotheca about which are disposed the three usual nematothecae seen on the hydrothecae of non-specialized hydrocladia, and in addition, a mesial nematotheca above the cup; hydrothecae on gonohydrocladia usually with poorly developed marginal teeth; costae number 17 to 20 pairs and grow out from between the hydrotheca and mesial infrathecal nematotheca and carry on their distal edge about seven nematothecae similar to the lateral nematothecae flanking the hydrothecae; the costal apophysis is small, subtriangular and arises from the base of the distal edge of the costa; each costal apophysis unites with the hinder edge of the base of the costa distal to it; the proximal edge of the broad costae also unite, usually at two points, with the distal edge of the costa proximal to it; the costae in the median region of the corbula appear to have a small nematotheca at the distal end on the proximal side.

Locality. Type locality, Chatham Rise, Stn. 52, 260 fathoms; (Chatham Expedition, 1954), 10/2/54. Type microslide—Chatham Exped. Slide No. 24.

In general, erect stem habit and size in Thecocarpus subdichotomus is very similar to that of Thecocarpus calycifera (Bale, 1914) and the similarity extends also to some characters of the hydrotheca and the corbula. Nonetheless, the nematothecae on both the hydrocladia and the specialized branches of the corbula of T. subdichotomus readily distinguish it from P. calycifera. Bale (1914) emphasises the cup-like nature of the nematothecae of T. calycifera which are widest at the aperture, as the terminal and lateral openings “cut(ting) into each other”. This characteristic of the nematothecae was readily observed in the microslide of T. calycifera on loan from the Canterbury Museum, Christchurch. In T. subdichotomus the nematothecae are narrow and taper towards the aperture, and both the terminal and lateral openings are quite separate, although fairly close together. A further feature distinguishing T. subdichotomus from T. calycifera is the number of septal ridges in the hydrocladial internode. There are four ridges in T. subdichotomus and only two in T. calycifera. Also, T. subdichotomus has five lateral pairs of marginal teeth on the hydrotheca and T. calycifera has only three. The corbula of T. subdichotomus and T. calycifera are very similar, as both possess three series of modified hydrocladia, but the longer spur of the gonohydrocladium, the greater number of broad costal leaflets (17 to 20 pairs—twice the number in T. calycifera) and the lack of outwardly directed wings on the free distal edge of the leaflets distinguish the corbula of T. subdichotomus from that of T. calycifera.

Aglaophenia Lamouroux, 1816

Erect stems usually rooted by filiform stolons; stems may, or may not be branched; hydrocladia pinnately arranged; margin of hydrotheca usually with teeth or lobes; margin of hydropore usually lacking tiny needle-like projections; associated with each hydrotheca on the non-specialized hydrocladia, is a median anterior nematotheca and two lateral nematothecae flanking the hydrotheca; lateral nematothecae frequently tubuliform; no other nematothecae on the non-specialized hydrocladia other than those associated with the hydrotheca; gonosome protected by accessory structures forming a corbula; secondary hydrocladium I lacking a hydrotheca at the base.

Four species, Aglaophenia plumosa Bale, 1882, A. acanthocarpa Allman, 1876, A. laxa Allman, 1876 and A. filicula Allman, 1883 have been recorded from New Zealand and all except A. filicula are represented in the present collection. Bale (1924) regarded Hilgendorf’s (1898) description of the latter species inadequate for identification. Hilgendorfs material appears to be lost.

The gonosome of the specimens described by Totton (1930) as Thecocarpus

ctenatus indicates that it is a species of the genus Aglaophenia. The gonohydrocladium lacks the characteristic basal theca (Totton, 1930, p. 237) of species of the genus Thecocarpus and “T” ctenatus is described here as a species of the genus Aglaophenia.

A. acanthocarpa is now quite well known from both North and South Island waters; A. plumosa from east coast South Island waters and Stewart Island; A. laxa is best known from North Island waters and A. ctenata is rare, known only from off the Three Kings Islands, and from the Chatham Rise. All the species of Aglaophenia described here have been taken elsewhere except A. ctenata. A. plumosa is recorded from Australia, Tasmania and South Africa; A. laxa from Torres Strait, and A. acanthocarpa from the Kermadec Islands. A. plumosa occurs mainly in the intertidal zone, while A. acanthocarpa, A. laxa and A. ctenata are better known from the sublittoral zone.

Key to the New Zealand Species of Aglaophenia

1 (4) Abcauline wall of hydrotheca with prominent intrathecal inwardly directed fold and/or ridge (Fig. 9, b and g).

2 (3) Lateral margin of hydrotheca with well developed pointed teeth A. ctenata (Totton, 1930)

3 (2) Lateral margin of hydrotheca with everted marginal lobes; anterior median tooth very well developed, sharply pointed, and projecting outwards A. plumosa Bale, 1882.

4 (1) Abcauline wall of hydrotheca without intrathecal fold or ridge.

5 (6) Length to breadth of hydrotheca approximately 2:1; mesial nematotheca usually extending beyond the margin of the hydrotheca; in front view the distal aperture of the mesial nematotheca can be seen to be as wide, or wider, than at the base; hydrocladia close together, growth habit compact and erect stem fairly rigid . A. acanthocarpa Allman, 1876

6 (5) Length to breadth of hydrotheca approximately 2.5:1; mesial nematotheca usually not extending beyond the margin of the hydrotheca; in front view, the mesial nematotheca is seen to narrow abruptly at the distal end, and terminate in a short tubular process (Fig. 10, b) hydrocladia distant, growth habit lax and erect stem flexible A. laxa Allman, 1876

Aglaophenia ctenata (Totton, 1930). Fig, 9, a-b.

1930. Thecocarpus ctenatus, Totton, p. 237, Text-fig. 69, a.

Erect stem of (?) medium height, largest known stem, incomplete, and 5.5 cm in length; stems arising from branched hydrorhizae; stem polysiphonic, the accessory tubes constricted diagonally at intervals to allow the stem to twist; stems unbranched, hydrocladia regularly alternate, one per stem internode, and very long up to 3.5 cm; distance between bases of hydrocladia on stem approximately 0.55 mm; stem, 0.20 to 0.25 mm in width measured at the node; stem apophysis approximately 0.15 mm in length; nodes transverse, not easily observed on the stem but dividing the hydrocladia regularly into thecate internodes; internodes of hydrocladia from 0.55 to 0.60 mm in length and 0.15 to 0.175 mm in width; hydrothecae deep, with two large intrathecal ridges, one on the abcauline side below the margin, and the other on the adcauline side near the base of the hydrotheca; both intrathecal ridges are prominent, particularly that on the adcauline side, and project approximately half-way across the hydrothecal cavity; hydrotheca conspicuously constricted on the adcauline side in the region of the ridge; margin of hydrotheca with a small, sharply pointed median anterior tooth and three lateral pairs of shallow rounded teeth; a small septal ridge in the internode at approximately the level of the adcauline intrathecal ridge; length of abcauline wall of hydrotheca 0.30 to 0.32 mm; width of hydrotheca at the margin, viewed laterally, 0.17 to 0.20 mm; nematotheca—mesial nematotheca, from 0.29 to 0.35 mm in length, fixed to the hydrotheca almost to the level of the abcauline ridge; mesial nematotheca narrowing at the distal end, free for

approximately one quarter of its length, with a single terminal gutter-like aperture, and lacking an opening into the hydrotheca; a septum at the base of the mesial nematotheca and a conspicuous subterminal thickening of the abcauline wall; lateral nematothecae flanking the hydrotheca, approximately 0.15 mm in length, elongate, sac-like, but tapering gradually to the distal region; terminal and lateral opening confluent, and showing a single gutter-like opening; stem nematothecae, four per internode—three with gutter-shaped apertures, disposed one on the anterior face at the base of the hydrocladium and two, well separated, on the front of the internode and the other a large curved tubular nematotheca lying horizontally across the internode at the same level as that at the base of the hydrocladium but with the terminal aperture directed outwards (Fig. 9, a): gonosome, “an open corbula of seventeen pairs of short gonohydroclades without theca; gonohydroclades give rise to longer costae, and have three dorsal nematothecae and one median below origins of costae; costae with five pairs of nematothecae and one apical; gonoclade with two nematothecae to each article, representing infrathecal and anterior supracalycine, and a single adorsal one” (Totton, 1930).

Locality. Type locality, off Three Kings Islands, New Zealand, 300 fathoms (Totton, 1930): Chatham Rise, R.R.S. “Discovery II”, Stn. 2733, 300 metres (W. H. Dawbin), 4/11/50, 145. Species known only from New Zealand waters.

The specimen in the present collection of A. ctenata is an infertile monosiphonic stem fragment 4.0 mm in length, but the two distinctive intrathecal ridges and other hydrothecal and stem characters leave no doubt as to its identity. Totton (1930) describes only three stem nematothecae per intemode. The present specimen has a fourth nematotheca alongside that at the base of the hydrocladium.

Aglaophenia plumosa Bale, 1882. Fig. 9, f-g.

1882. Aglaophenia plumosa Bale, p. 37. 1884. Aglaophenia plumosa Bale. Bale, p. 153, PI. xiv, fig. 5; PI. xvii, fig. 12. 1924. Aglaophenia plumosa Bale. Bale, p. 257 (synonymy). 1942. Aglaophenia plumosa Bale. Blackburn, p. 110. 1950. Aglaophenia plumosa Bale. Hodgson, p. 56, fig. 87.

Erect stem short, up to 4.0 cm in length, arising singly from reticulate hydrorhizal stolons; monosiphonic, unbranched, hydrocladia carried directly on the main stem, pinnately arranged arising fronto-laterally from the stem, close together, alternate, both series directed towards the front; 2.0 to 3.0 mm at the base of the stem lacking hydrocladia; non-hydrocladial bearing basal internodes with from three to six nematothecae; hydrocladia approximately 3.0 mm in length; hydrocladial nodes slightly oblique dividing the hydrocladia regularly into thecate internodes; stem internodes from 0.190 to 0.32 mm in length and 0.17 to 0.275 mm in width; stem apophyses 0.10 to 0.15 mm in length; internodes of hydrocladia from 0.20 to 0.33 mm in length and 0.10 to 0.13 mm in width; hydrotheca, elongate, erect, almost parallel with the axis of the internode; two intrathecal ridges, one very short and thick at the base of the median anterior tooth on the abcauline side and the other, also small, on the adcauline wall towards the base of the hydrotheca; aperture set at approximately 45° to the long axis of the internode; margin of hydrotheca with very well developed, pointed, slightly incurved, median anterior tooth; lateral margins forming an everted, angular lobe which slopes rather sharply down towards the back of the cup and the internode; abcauline length of hydrotheca from 0.19 to 0.27 mm, and hydrotheca 0.125 to 0.160 mm at the margin viewed laterally; two septal ridges across the internode, one at the level of the adcauline intrathecal ridge and the other at the base of the lateral hydrothecal nematothecae; nematothecae—mesial nematotheca long, 0.225 to 0.30 mm in length, fixed to the abcauline wall of the hydrotheca for approximately half its length; free portion of mesial nematotheca more or less tubular, diverging outwards from the hydrotheca and with distinct terminal and lateral apertures as well as an internal opening into the hydrotheca; lateral nematothecae flanking the hydrotheca approximately 0.12 mm in length, tubular, fixed to the hydro theca as far as the hydrothecal margin, free portion directed forwards and outwards and with distinct lateral and terminal apertures; stem nematothecae located at the base of the hydrocladium, two in number with gutter-like aperture: gonosome, borne on a modified hydrocladium which forms a protective corbula; corbula open, approximately 5.0 mm in length, including the basal peduncle; basal peduncle with one hydrothecate internode; internodes of rachis short, approximately 0.15 mm in length, and with two nematothecae disposed at the base of each gonohydrocladium; 15 to 20 pairs of alternate gonohydrocladia; each gonohydrocladium with two series of tubular nematothecae; nematothecae opposite or subalternate, but the two proximal nematothecae on the distal edge of the gonohydrocladium without corresponding nematothecae on the proximal edge; gonohydrocladia of each series arched and meeting at the tips; distinct transverse nodes above the proximal nematotheca which is larger than all the others and may be forked.

Locality. Type locality, Aldinga, South Australia (Bale, 1882): Quail Island, Gladstone Pier, Lyttelton Harbour (G. Knox), 25/6/53, 409; and, Lyttelton Harbour (Bale, 1924); Menzies Bay, Bank’s Peninsula (G. Knox), -/8/49, 240; Portobello Marine Biological Station, reef (E. J. Batham), 26/3/51, 180; Stewart Island (Ringa Ringa), Mrs. E. Willa, 8/11/56, 528.

Distribution. Australia; Tasmania; New Zealand; South Africa.

A. plumosa was recorded first from New Zealand by Bale (1924), and not recorded again until the present paper. The species appears to be of fairly widespread occurrence in the Lyttelton and Port Chalmers harbour areas and is known from one Stewart Island locality but not from North Island waters. A. plumosa is the only species of Aglaophenia known from New Zealand waters in which the lateral margin of the hydrotheca lacks teeth and has everted marginal lobes.

Aglaophenia acanthocarpa Allman, 1876. Figs. 9, h-j; 10, g.

1876 a. Aglaophenia acanthocarpa Allman, p. 274, PI. XXI, figs. 1-4. 1911. Aglaophenia laxa of Hilgendorf, p. 541, not A. laxa Allman, 1876. 1916. ? Aglaophenia divaricata var. acanthocarpa of Jaderholm, p. 18. 1924. Aglaophenia acanthocarpa Allman. Bale, p. 258, fig. 14 (synonymy). 1926. Aglaophenia acanthocarpa Allman. Bale, p. 23. 1928. ? Aglaophenia acanthostoma Allman. Trebilcock, p. 25. 1930. Aglaophenia acanthocarpa Allman. Totton, p. 235.

A small species with erect stem up to 8.0 mm in length, often arising trom a tangieu mass of hydrorhizal stolons; monosiphonic, stems either branched or unbranched; “branches" in reality secondary stems arising from hydrorhizal tubes that have grown up the stem; primary stem smooth for the first one or two millimetres, then a portion of variable length, bearing a row of nematothecae, and lastly, the stem regularly divided by transverse nodes into internodes, from which the hydrocladia arise, one per internode, and from the frontolateral aspect; hydrocladia borne on a stem apophysis approximately 0.09 mm in length; hydrocladia up to 3.5 mm in length; secondary stems (“branches”) divided by nodes into non-thecate internodes for the first one or two millimetres, thereafter each internode carries a hydrocladium; stem internodes from 0.22 to 0.30 mm in length and 0.19 to 0.30 mm in width; internodes of hydrocladia from 0.200 to 0.275 mm in length and 0.11 to 0.14 mm in wiain; hydrothecae deep, length to breadth ratio most frequently 2:1; an adcauline intrathecal ridge towards the base of the hydrotheca and a fold from it nearly surrounds the hydrotheca; hydro theca set at an angle of from 40° to 45° to the long axis of the internode; margin of hydrotheca with prominent teeth, a median anterior tooth sharply pointed and with a small angular erect crest, and four pairs of lateral teeth, the first wide, the second and third triangular, and the fourth tiny and not readily observed in side view; second lateral tooth everted and the largest of the laterals; abcauline length of hydrotheca approximately 0.25 mm; width of hydrotheca at margin 0.13 to 0.15 mm viewed laterally; two septal ridges across the internode, one at the level of the intrathecal ridge and the other at the base of the lateral nematothecae; in general neither septal ridge extends right across the internode; nemaiothecae—mesial nematotheca 0.29 to 0.35 mm in length, fixed to the abcauline wall of the hydrotheca almost to the margin and then projecting outward, and upward, free portion forming a tube nearly equal in diameter from lateral aperture to the tip; terminal aperture and lateral aperture well separated and readily observed; an opening from mesial nematotheca into hydrotheca; lateral nematothecae flanking the hydrotheca approximately 0.125 mm in length, fixed to the hydrotheca as far as the margin with the short free portion directed forward and upward; lateral nematothecae largest on hydrothecae at the distal end of the hydrocladium; terminal and lateral aperture distinct; stem nematothecae positioned at the base of the hydrocladia on the stem apophysis: two in number, broader than but similar to the laterals flanking the hydrotheca: gonosome, borne on a modified hydrocladium which forms a protective corbula; corbula open, approximately 4.0 mm in length including the basal peduncle; basal peduncle with one hydrothecate internode; internodes of rachis short, approximately 0.15 mm in length, and each is provided with a median and inner nematotheca with gutter-like aperture; gonohydrocladia borne on fronto-lateral apophysis of the rachis internodes; approximately 25 pairs of gonohydrocladia on fully grown corbulae; each gonohydrocladium with a basal median and a distal lateral nematotheca; arching costae arise from the gonohydrocladia of each side, and tips of the two series of costae meet in mid line; costae divided by transverse nodes into internodes, each of the latter with a pair of opposite long, slightly-curved tubular nematothecae, except the two internodes at the base, which usually have only one nematotheca; gonangia arise from the rachis in the axils of the gonohydrocladia.

Locality. Type locality, “New Zealand” (Allman, 1876): Kawhia Harbour (C. Trevarthen), -/5/50, 734; Whatipu, Auckland, -/3/50 (G. Trevarthen), 735; Lyall Hay, Cook Strait, storm drift (Gram), 14/8/51, 190; Palliser Bay, Cook Strait, on appendage oi Jasus lalandii (R. W. Zander), 6/9/56, 491; rh 5 miles North of Taiaroa Heads, 18-20 fathoms (E. J. Batham), 27/11/53, 733; St. Clair, Dunedin, and Bluff, Southland (Trebilcock, 1928); Golac Bay, Foveaux Strait, storm drift (G. Knox), 4/1/53, 402.

Distribution. New Zealand; Kermadec Islands.

The present material is the largest collection to date of A. acanthocarpa irom New Zealand waters, and considerably extends the previously known distribution range. The specimens described by Bale (1924), and briefly recorded by Totton (1930), were British Museum (Natural History) type specimens. Trebilcock (1928) records an Aglaophenia “ acanthostoma” Allman from St. Clair and Bluff but gives no description.

The stem characters described by Bale (1924) for A. acanthocarpa have been observed in all the present material. The marginal teeth of the hydrotheca, however, are more variable in size and shape than was thought previously, but then a much greater amount of material is now available. Bale describes and figures the second and third laterals as triangular. In some of the present specimens these teeth are as described by Bale, but in others they are broad and bluntly rounded (Fig. 9, h). Broad, second and third laterals, and pointed triangular ones, are often present on hydrothecae of the same stem. Bale also observed two septal ridges in the intemode of A. acanthocarpa. Three septal ridges is a common occurrence in the present specimens with the basal ridge about half the size of the medial and distal ridges. As with the variation in shape of the lateral hydrothecal teeth, the variation in size of the septal ridges does not appear to be restricted to stems from any one locality.

A. acanthocarpa Allman and A. laxa Allman both described from “ New Zealand ” in 1876, have in the past been confused one with the other and A. acanthocarpa with A. divaricata (Busk). Bale (1924) clearly distinguished A. acanthocarpa from both A. laxa and A. divaricata, the latter not known from New Zealand. The present material of A. acanthocarpa has revealed other differences between A. acanthocarpa and A. laxa. The erect stem of A. acanthocarpa is much stiffer than that of A. laxa, and the hydrotheca is shorter in relation to the width, 2:1 than in A. laxa, where it is approximately 2.5:1. In front view (Figs. 9, i; 10b) further differences can be distinguished between the hydrothecae of the two species. In A. acanthocarpa the mesial nematotheca is broader at the distal end than the proximal, while in A. laxa the distal end is prolonged into a short, narrow, tubular projection. Furthermore the nematotheca is usually fixed to the abcauline wall almost to the margin in A. acanthocarpa, but below the margin in A. laxa although this condition in the latter species is rather variable and the mesial nematotheca may be adnate almost to the margin as in A. acanthocarpa. The median anterior tooth in A. acanthocarpa has an angular erect crest, while that of A. laxa has a semicircular crest.

Comparison of the present material of A. acanthocarpa with Australian specimens of A. divaricata shows the base of the hydrotheca of A. acanthocarpa as narrow and not so deeply immersed in the internode as that of A. divaricata and the mesial and lateral nematothecae associated with the hydrotheca are different and further distinguish the two species. These hydrothecal characters are readily observed and were noted by Bale (1924).

More recently (Blackburn, 1942) included A. acanthocarpa in the synonymy of A. ramulosa Kirchenpauer. The hydrothecae of A. acanthocarpa have a general similarity of shape to those of A. ramulosa but the mesial nematotheca of A. ramulosa appears to be longer and much more erect than that of A. acanthocarpa. The mesial nematotheca of A. acanthocarpa is, however, more variable in length but not in angle of projection, than was thought previously, and sometimes extends beyond the

margin of the hydrotheca almost as far as that of A. ramulosa. Bale (1924) when discussing the status of A. acanthocarpa makes no mention of it being a possible synonym of A. ramulosa but instead discusses its characteristics relative to those of A. divaricata, a species with which A. acanthocarpa had been confused. Furthermore, Bale had examined the type material of both A. ramulosa (cf. Bale, 1884) and A. acanthocarpa (cf. Bale, 1924) and in addition had a very wide knowledge of the status of Australasian hydroid species. As material of A. ramulosa has not been available for study and discussion in this paper, it seems better in the meantime to consider A. acanthocarpa a distinct species.

Aglaophenia laxa Allman, 1876. Fig. 10, a-c. 1876 a. Aglaophenia laxa Allman, p. 275, PI. XXI, figs. 5-7. 1924. Aglaophenia laxa Allman. Bale, p. 260, fig. 15 (synonymy). 1928. Aglaophenia laxa Allman. Trebilcock, p. 25, PI. V, figs. 5-sb. 1930. Aglaophenia laxa Allman. Totton, p. 233, Text-figs. 67-68.

A small species with erect stem up to 6.0 cm in length, often arising from a tangled mass of hydrorhizal stolons; monosiphonic, stems either branched or unbranched; “branches” irregular, all lying in the same plane; “branches” in reality, secondary stems arising from hydrorhizal tubes that have grown up the stem; ostia present between stem and secondary hydrorhizae; primary stem smooth for the first two or three millimetres, then a region of variable length bearing a row of nematothecae and lastly, the stem is regularly divided by transverse nodes into internodes from which the hydrocladia arise, one per internode, from the fronto-lateral aspect; hydrocladia from 4.0 to 6.0 mm in length; secondary stems (“branches”) divided by nodes into non-thecate internodes for two or three millimetres, thereafter each internode carries a hydrocladium; stem internodes from 0.175 to 0.275 mm in length and 0.15 to 0.20 mm in width; internodes of hydrocladia from 0.20 to 0.24 mm in length and approximately 0.10 mm in width; hydrothecae deep, rather narrow at the base, gradually widening towards the aperture; length to breadth ratio most frequently, about 2.5:1; a well developed adcauline intrathecal ridge towards the base of the hydrotheca; margin of hydro theca with prominent teeth, a median anterior tooth, sharply pointed and with a small semicircular crest, and four lateral pairs of teeth, the second being the largest and strongly everted; abcauline length of hydrotheca from 0.20 to 0.25 mm; width of hydrotheca at margin approximately 0.14 mm viewed laterally; three septal ridges across the internode, the proximal ridge at the base of the hydrotheca is very small, the medial ridge at the level of the intrathecal ridge is well developed and horizontal, and extends right across the internode, and the distal ridge at the base of the lateral nematotheca is oblique, also well developed and extends across the internode; nematothecae—mesial nematotheca, approximately 0.21 mm in length, fixed to the abcauline wall of the hydrotheca for approximately a third of its length; free portion diverging outwards and upwards from the hydrotheca almost to the hydrothecal margin, more or less tubular as seen in lateral view and with distinct terminal and lateral apertures; in front view the mesial nematotheca shows a short, narrow, tubular prolongation (Fig. 10b) and a small opening into the hydrotheca; lateral nematothecae from 0.10 to 0.15 mm in length, flanking the hydrotheca, tubular, fixed to the internode as far as the margin, free portion extending slightly outwards and upwards a little beyond the hydrothecal margin and with terminal and lateral apertures; stem nematothecae two in number, located at the base of each hydrocladium: gonosome, borne on a modified hydrocladium which forms a protective corbula; corbula open, approximately 6.0 mm in length including the basal peduncle; basal peduncle with one hypothecate internode; internodes of rachis short, approximately 0.15 mm in length, and each is provided with a median and inner nematotheca with gutter-like aperture; gonohydrocladia borne on a fronto-lateral apophysis of the rachis internodes; approximately seventeen pairs of gonohydrocladia; each gonohydrocladium with a distal asymmetrical pair of nematothecae and a basal median nematotheca; arching costae arise from the gonohydrocladia of each side, opposite the two distal nematothecae; tips of the two series of costae meeting at the mid-line; costae divided by transverse nodes into internodes each with a pair of opposite nematothecae, except the basal internode, which has only one nematotheca; gonangia arise from the rachis in the axils of the gonohydrocladia; male and female corbulae of similar structure but borne cn separate stems.

Locality. Type locality “New Zealand” (Allman, 1876): near North Cape, Stn. 134 “Terra Nova” 11-20 fathoms; off Gape Maria van Diemen, Stn. 144, “Terra Nova”, 40 fathoms (Totton, 1930); Opunake Beach, Bay of Plenty, storm drift (P.M.R.), -/2/53, 313; Island Bay, Cook Strait (Trebilcock, 1928); Lyall Bay, Wellington (cf. Totton, 1930);

Paraparaumu Beach, West Coast, North Island, storm drift (P.M.R.), 5/1/52, 269; New Brighton, Christchurch (E. W. Bennett), ~/4/23, 133.

Distribution. New Zealand; Torres Straits (cf. Totton, 1930).

Further collection will probably show that A. lax a is of widespread occurrence in New Zealand waters. The present material extends the previously known latitudinal range southward from Cook Strait to the Christchuch area so that A. laxa ranges on the eastern coasts of New Zealand from Cape Maria van Diemen in the North at approximately 34° S. to Christchurch about 43° S, The stem and gonosome characters of the present specimens of A. laxa are as described by Bale (1924) and Totton (1930).

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Patricia M. Ralph, M.Sc., Zoology Department,

Victoria University of Wellington, P.O. Box 196, Wellington, N.Z.