Art. XXIV.—Descriptions of New Species of New Zealand Land and Fresh-water Shells.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 22, 1889, Page 221

Art. XXIV.—Descriptions of New Species of New Zealand Land and Fresh-water Shells. By H. Suter. [Read before the Philosophical Institute of Canterbury, 7th November, 1889.] Plates XIV. and XV. Shortly after arrival in this beautiful colony, in January, 1887, I began to collect land and fresh-water shells, for a few weeks near Wellington, and afterwards, up to October of last year, in the southern part of the Forty-mile Bush. Since November, 1888, I have collected in the neighbourhood of the Mount Cook Hermitage. I have succeeded in finding a considerable number of new species, all, with a few exceptions, very small and scarce. This circumstance explains fully why they hitherto have been overlooked. In the following pages I wish to give the descriptions of all the new shells I found in the Forty-mile Bush, and of two from the Hermitage. Next winter I hope to be able to complete this paper by giving the descriptions of the animals, as far as they are known to me, their position in the system, and descriptions of some more new species found near the Hermitage. It is an agreeable duty for me to tender my best thanks to Professor F. W. Hutton, who from the very first assisted me so kindly, up to the present day, with his great knowledge in conchology. I have also to thank Professor A. Mousson, of Zürich, for his valuable communications on New Zealand Mollusca. Helix pseudoleioda, n. sp. Plate XIV., fig. 1, a—c. Shell small, globose, yellowish-white, banded with some-what backwards-directed brown streaks, faintly shining, closely ribbed, ribs on upper surface straight, a little undulating outside; ribs about 38 in the tenth of an inch (15 per mm.). Spire globosely elevated, less rounded at the base. Whorls 6, round, very slowly increasing, the last not descending. Suture pretty deep. Aperture lunately rounded, slightly oblique, excavated by the penultimate whorl. Peristome straight, not dilated, acute, margins distant, columellar margin slightly descending. Aperture with 12 laminæ—3 on the penultimate whorl, 1 on the columella, and 8 on the parietal wall. The lowest plait on the penultimate whorl is strongly developed; the plait on the columella also is relatively large, tongue-shaped; the laminæ on the parietal wall are fine, long, the four lower ones are more approached than the others. Umbilicus very narrow, deep, open.

Diameter, 0.09in. (2.25mm.); height, 0.06in. (1.5mm.). Hab. Under rotten wood and bark in the bush. Not common. North Island: Forty-mile Bush; Hastwell, Mauriceville. (H. S.) The external appearance is nearly the same as in Helix leioda, Hutton: that is why I gave it the name of pseudoleioda. It is easily distinguished from H. leioda, Hutt., having only 12 laminæ in the aperture, whilst the other has 18. Helix wairarapa, n. sp. Plate XIV., fig. 2, a—c. Shell depressed, small, light horny brown with brown streaks, which are irregular in breadth, faintly shining, fragile, with close and fine ribs, which are somewhat undulating. Ribs about 38 in the tenth of an inch (15 per mm.). Spire little elevated, nearly flat. Whorls 6, slowly increasing, narrow, the last not descending, rounded. Suture deeply impressed. Aperture slightly oblique, lunately rounded, considerably excavated by the penultimate whorl. Peristome straight, not dilated, acute, margins slightly convergent. Columellar margin not reflected, descending. Aperture with 16 laminæ—5 on the penultimate whorl, 1 on the columella, and 10 on the parietal wall. Of the laminæ on the penultimate whorl the four inferiors are close together, the superior at some distance, all showing the same development. The lamina on the columella is more developed, conical. The laminæ on the parietal wall are fine, long, and nearly regularly distributed over the whole surface. Umbilicus wide, perspective, deep, one-third of the diameter. Diameter, 0.07in. (1.75mm.); height, 0.04in. (lmm.). Hab. Under rotten bark in the bush. Not common. North Island: Forty-mile Bush; Hastwell. (H. S.) Helix hectori, n. sp. Plate XIV., fig. 3, a—c. Shell small, depressed, discoidal, light horny brown with large close brown streaks, not shining, fragile, transparent closely ribbed, ribs nearly straight, about 38 in the tenth of an inch (15 per mm.). Spire nearly flat. Apex bare of epidermis, light-grey. Whorls 5, very slowly but regularly increasing, rounded, the last not descending. Suture impressed. Aperture slightly oblique, rotundly lunar, excavated by the penultimate whorl. Peristome acute, straight, margins convergent. Columellar margin not reflected, descending. Aperture with 14 laminæ—5 on the penultimate whorl, 2 on the columella, and 7 on the parietal wall. On the middle of the penultimate whorl is a stout lamina, which is divided in two by a deep groove, thus getting forked; the other four smaller laminæ are below this one. The laminæ on the columella are

well developed, the inner one with two or three sharp points, the second high, in the shape of a sharp tooth. The plaits on the parietal wall are rather stout, elevated, not very long, and regularly distributed. Umbilicus broad, deep, perspective, nearly one-third of the diameter. Diameter, 0.09in. (2.25mm.); height, 0.04in. to 0.05in. (1mm. to 1.25mm.). Hab. Under rotten bark. The most common of the group. North Island: Forty-mile Bush; Hastwell. (H. S.) Named in honour of Sir James Hector, to whom I am greatly indebted for assistance in my studies of natural history. Helix microundulata, n. sp. Plate XIV., fig. 4, a—d. Shell depressed, very small, pale horny, with neat brown streaks which are sometimes sharply undulating, otherwhiles forming zigzag lines, but varying in breadth; faintly shining, fragile, with very close ribs. Ribs bent a little forwards on the surface, then going straight downward—60 in the tenth of an inch (25 per mm.). Spire very little elevated, nearly flat; apex bare. Whorls 5, slowly increasing, rounded, the last not descending. Suture impressed. Aperture slightly oblique, rotundly lunar, more excavated in the upper part by the penultimate whorl. Peristome straight, acute, margins not convergent, regularly arched, columellar margin descending. Aperture with 13 laminæ—1 on the penultimate whorl, 2 on the columella, and 10 on the parietal wall. The plait on the penultimate whorl is central, high, but rather thin, forked at the top by a deep and large groove. The two laminæ on the columella are stout, with large base, and both tongue-shaped. The plaits on the parietal wall are fine, long, regularly distributed. Umbilicus deep, broad, nearly one-third of the diameter. Diameter, 0.07in. (1.75mm.); height, 0.04in. (1mm.). Hab. Under rotten wood and bark in the bush. Very rare. North Island: Forty-mile Bush; Hastwell. (H. S.) Middle Island: Greymouth. Found one specimen amongst Helix leioda, Hutt., sent to me by Mr. R. Helms. Helix aorangi, n. sp. Plate XIV., fig. 5, a—c. Shell small, depressed, globular, yellowish-white, with somewhat irregular chestnut zigzag or sinuated streaks, faintly shining, thin, transparent. With well-developed ribs, nearly straight, about 38 in the tenth of an inch (15 per mm.). Whorls 5½ to 5, slowly increasing, rounded. Suture impressed. Aperture slightly oblique, rotundly lunar, regularly excavated by the penultimate whorl. The last whorl not descending. Aperture straight, acute, margins slightly

convergent; columellar margin descending, not reflected. Aperture with 12 laminæ—1 on the penultimate whorl, 2 on the columella, and 9 on the parietal wall. The lamina on the penultimate whorl is a little above the centre, high, rather thin, and forked by a deep and broad groove. The two laminæ on the columella are stout, with large base, and tongue-shaped, the first rather sharp. The nine lamellæ on the parietal wall are fine and long—the five lower ones a little stouter, and separated from the other four by a somewhat larger interval. Umbilicus deep, perspective, not very broad, about onequarter of the diameter. Diameter, 0.08in. (2mm.); height, 0.05in. (1.25mm.). Hab. Under dead leaves and rotten wood in the subalpine bush. Rather scarce. Middle Island: Environs of the Mount Cook Hermitage. (H. S.) This species is closely allied to H. microundulata, but it is somewhat larger, more globose, with stronger and more distant ribs. The laminæ of the aperture are nearly equal in both species, but H. aorangi has only nine laminæ on the parietal wall. Helix pseudoleioda, wairarapa, hectori, microundulata, aorangi, and H. leioda, Hutton, form together a peculiar and, I think, quite new group, to which I propose to give the name of Huttonella, in honour of Prof. F. W. Hutton, who first described a species of this group. Patula infecta, Reeve, var. irregularis, n. var. Plate XIV., fig. 6, a, b. Shell depressed, subdiscoidal, yellowish-white with distant light-brown streaks vanishing on the base, slightly shining, rather thin, transparent; strongly plaited, plaits directed forwards on the surface, and a little undulated descending; about 30 in the tenth of an inch (12 per mm.). The ribs are irregularly developed and distant. Spire slightly elevated. Whorls 5½ to 5, narrowly rolled up, very slowly increasing, rounded, the last very slightly descending. Suture not deep. Aperture rotundly lunar, but little excavated by the penultimate whorl, slightly oblique. Upper margin advancing. Margins straight, convergent, acute; columellar margin nearly vertically descending. The parietal wall inside a little callous, white. Umbilicus broad, perspective, showing all the whorls, about one-third of the diameter. Diameter, 0.12in. (3mm.); height, 0.06in. (1.5mm.). Hab. Under rotten logs and dead leaves. Very scarce. North Island: Forty-mile Bush; Hastwell. This variety is distinguished from P. infecta by the slightly-elevated spire, the faint indistinct markings; it is narrowerribbed, the ribs being irregular in distance and development;

there is one-half to one whorl less, and the diameter of the shell is smaller. Patula colensoi, n. sp. Plate XIV., fig. 7, a, b. Shell discoidal, yellowish-grey, zigzag streaks of dark-brown flowing sometimes together, rather solid, transparent, faintly shining; with strong plaits, directed forwards on the surface, slightly undulating on the side; the interstices striated with growth-lines. Ribs about 20 in the tenth of an inch (8 per mm.). Spire flat. Whorls 5, narrow, slowly increasing, rounded, the last not descending, tapering. Suture deep. Aperture slightly oblique, rotundly lunar, little excavated by the penultimate whorl, margins convergent. Umbilicus broad, perspective, showing all the whorls, about one-third of the diameter Diameter, 0.16in. (4.25mm.); height, 0.06in. (2.25mm.). Hab. Under rotten wood and dead leaves in the bush. Rather scarce. North Island: Forty-mile Bush; Hastwell. (H. S.) Named in honour of the Rev. William Colenso, F.R.S., the discoverer of the Unio waikarense. This species is near Pat. infecta, Reeve, but differs sufficiently from it to justify the creation of a new species: the direction of the ribs on the surface is different; there are only 5 whorls, more rapidly increasing, and the last considerably more developed; the peristome has no callosity; the umbilicus is a little narrower; the diameter is more considerable, the colour darker, the ribs coarser and rather more distant. Patula variecostata, n. sp. Plate XIV., fig. 8, a-c. Shell discoidal, small, white with large yellow streaks at regular distances, faintly shining, fragile, transparent, with close fine ribs, directed forwards on the surface and going straight down on the side; there is alternately one much higher than the next; interstices striated with growth-lines and reticulated with spirals. Ribs about 38 in the tenth of an inch (15 per mm.). Spire flat, only the first whorls a little elevated. Whorls 5, slowly and regularly increasing, swollen, the last not descending. Suture very deep. Aperture slightly oblique, rotundly lunar, but little excavated by the penultimate whorl. Peristome straight, acute, somewhat tapering, columellar margin nearly vertically descending, upper and lower margin strongly arcuated. Umbilicus broad, perspective, about one-third of the diameter. Diameter, 0.07in. (1.8mm.), not quite adult; height, 0.04in. (1mm.). Hab. Under rotten pieces of wood. Very rare. North Island: Mauriceville. (H. S.)

Patula raricostata, n. sp. Plate XIV., fig. 9, a, b. Shell small, depressed, subdiscoidal, colour dark olive, not shining, fragile, with distant, stout, dark-brown ribs, bent backwards on the surface and slightly undulating on the side. Ribs about 12 in the tenth of an inch (5 per mm.). Spire slightly elevated. Apex white, bare of epidermis. Whorls 5, slowly increasing, rounded, the last not descending. Suture not deep. Aperture oblique, nearly circular, but very little excavated by the penultimate whorl. Margins convergent. Columellar margin slightly reflected, descending vertically. Lower margin strongly arcuated. Umbilicus broad, deep, showing the last whorls, about one-quarter of the diameter. Diameter, 0.08in. (2mm.); height, 0.04in. (1mm.). Hab. In the mould, under dead leaves. Very scarce. The shell is always covered with mud. North Island: Mauriceville. (H. S.) Diplomphalus subantialba, n. sp. Plate XV., fig. 10, a, b. Shell small, discoidal, light-horny to white, somewhat shining, fragile, transparent, very closely and finely ribbed; ribs directed forwards, slightly undulating on the surface, straight on the side, about 90 ribs in the tenth of an inch (35 per mm.). Spire deeply concave, infundibuliform. Whorls 5—the first ones very narrow, the last very large, nearly two-thirds of the diameter; the inner whorls swollen, the last ascending rapidly on the inner side, and falling slowly arcuated to the periphery. Suture very deep. Last whorl not descending. Aperture lunar, small, vertical, strongly excavated by the penultimate whorl. Peristome straight, acute; upper margin narrowly, the lower larger arcuated. Margins convergent. Umbilicus large, deep, perspective, presenting nearly the same aspect as the surface. Diameter, 0.07in. (1.75mm.); height, 0.03in. (0.8mm.). Hab. Under rotten wood in the bush, on very damp places. North Island: Forty-mile Bush; Hastwell; Mauriceville. (H. S.) This shell is a good miniature of Helix antialba, Beddone, of Tasmania, but differs from it. I do not think I am wrong in placing our shell in the genus Diplomphalus, to which also belongs Pat. biconcava, Pf. Diplomphalus huttoni, n. sp. Plate XV., fig. 11, a, b. Shell small, discoidal, light-horny, with fine well-developed ribs, directed forwards and arcuated on the surface, slightly undulated on the periphery; about 40 ribs in the tenth of an inch (16 per mm.). Spire deeply concave, to about one-third of the height. Apex smooth, white, shining. Whorls 41/2, the inner ones narrow, the last largely developed, occupying two-

thirds of the diameter, not descending, on the inner side rapidly ascending, regularly arcuated to the periphery. Suture very deep. Aperture lunar, narrow, vertical, much excavated by the penultimate whorl. Peristome straight, acute; upper margin narrowly, lower broader arcuated; columellar margin vertically descending, margins convergent. Penultimate whorl smooth, white, rather callous. Umbilicus broad, deep, perspective, about one-third of the diameter. Diameter, 0.1in. (2.7mm.); height, 0.04in. (1.5mm.). Hab. Under rotten logs. Very scarce; only two specimens. North Island: Forty-mile Bush; Hastwell. (H. S.) Named in honour of Professor F. W. Hutton, F.G.S., to whom I am so greatly indebted for his assistance in conchology. Diplomphalus moussoni, n. sp. Plate XV., fig. 12, a, b. Shell small, discoidal, white banded with brown, the streaks following the direction of the ribs at irregular distances, faintly shining, thin, transparent, strongly ribbed; ribs sharp, directed forwards and arcuated on the surface, slightly undulating on the periphery, straight below, about 18 ribs in the tenth of an inch (7 per mm.). Spire concave to about one-quarter of the height. Apex smooth, shining. Whorls 4, the first 3 very narrow, the last large, two-thirds of the diameter, not descending, on the inner side rapidly ascending, regularly arcuated outside. Suture very deep. Aperture vertical, lunar, excavated by the penultimate whorl. Peristome straight, acute, lower margin regularly arcuated, the upper margin forming a much narrower arch; columellar margin descending nearly vertically, not reflected; margins convergent. Penultimate whorl smooth, white, somewhat callous to a short distance outside the aperture. Umbilicus broad, perspective, about one-quarter of the diameter. Diameter, 0.15in. (4mm.); height, 0.08in. (2mm.). Hab. Under rotten logs. Only two specimens. North Island: Forty-mile Bush; Hastwell. (H. S.) Named in honour of Professor A. Mousson, of Zürich, the distinguished conchologist, who has assisted me in any way he could for the last twenty years. Hyalina microreticulata, n. sp. Plate XV., fig. 13, a, b. Shell very small, globosely elevated, horny-fulvous, shining, very thin, pellucid, finely striated, reticulated between the striæ. Spire conical, elevated. Whorls 5, rounded, regularly increasing. Suture impressed. Aperture oblique, rotundly lunar, but little excavated by the penultimate whorl. Peristome straight, acute, margins faintly convergent; columellar

margin somewhat reflected, descending straight. Umbilicus narrow, deep. Diameter, 0.07in. (1.7mm.); height, 0.05in. (1.3mm.). Hab. In mould in the bush. Very scarce; only two specimens. North Island: Forty-mile Bush; Hastwell. (H. S.) Hyalina allochroida, n. sp. Plate XV., fig. 14, a-c. Shell very small, depressed; the first three whorls colourless, the penultimate yellowish-horny, and the last hornyfulvous; very thin, pellucid, with distant fine ribs, directed backwards on the surface and somewhat arcuated on the side; about 30 ribs in the tenth of an inch (12 per mm.). Distinctly reticulated between the ribs. Spire slightly elevated. Whorls 5, swollen, regularly increasing, the last not descending. Suture deep. Aperture slightly oblique, rotundly lunar, little excavated by the penultimate whorl. Peristome straight, acute, margins convergent, columellar margin slightly reflected, slightly bent downwards. Umbilicus very narrow. Diameter, 0.06in. (1.5mm.); height, 0.04in. (1mm.). Hab. Under dead leaves in mould. Scarce. North Island: In the bush, near Mauriceville. (H. S.) Doubtfully included in Hyalina. A variety occurs near the Mount Cook Hermitage. Hyalina allochroida, n. sp., var. sericata, n. var. Plate XV., fig. 15, a, b. Shell very small, depressed, yellowish-horny, thin, pellucid, closely and finely ribbed, ribs bent backwards on the surface, slightly undulating on the periphery; about 60 ribs in the tenth of an inch (25 per mm.). Spire slightly elevated. Whorls 5, slowly and regularly increasing, narrow, rounded, the last not descending. Suture deep. Aperture oblique, lunar, higher than broad, little excavated by the penultimate whorl. Peristome straight, acute, upper margin somewhat advancing, columellar margin not reflected, obliquely bent downwards. Umbilicus very narrow. Diameter, 0.05in. (1.2mm.); height, 0.03in. (0.7mm.). Hab. Under dead leaves and rotten wood in the bush. Found only one specimen. North Island: Forty-mile Bush; Hastwell. (H. S.) Hyalina allochroida, n. sp., var. lateumbilicata, n. var. Plate XV., fig. 16, a, b. Shell very small, depressed, yellowish-horny, shining, pellucid, thin, with rather distant ribs, bent backwards on the surface, oblique and undulated on the periphery. Interstices reticulated. Spire slightly elevated, apex smooth, colourless. Whorls 5, regularly and slowly increasing, narrow, rounded,

New Zealand Land Shells..

New Zealand Land Shells..

the last rather descending. Aperture very oblique, rotundly lunar, little excavated by the penultimate whorl. Peristome straight, acute, margins convergent; columellar margin slightly reflected, accurately bent downwards. Umbilicus open, deep, about one-fifth of the diameter. Diameter, 0.06in. (1.5mm.); height, 0.04in. (1mm.). Hab. Amongst dead leaves and mould in the bush. North Island; Forty-mile Bush; Hastwell. (H. S.) Limnœa alfredi, n. sp. Plate XV., fig. 17, a. Shell oblong, glossy, extremely thin and fragile, horncoloured, semi-transparent, longitudinally plaited. Apex blunt, very often eroded. Whorls 4, rather flattened. Suture deep. Aperture ovate, more than half the length of the shell. Peristome simple; the outer lip thin, not reflected; the inner lip slightly callously reflexed, covering the umbilicus. Columellar plait very small. Specimens from Governor's Bush Creek: Length, 0.3in. (7.5mm.); diameter, 0.16in. (4mm.); aperture—long 0.18in. (4.5mm.), broad 0.12in. (3mm.). Specimens from Birch Hill Lagoon: Length, 0.37in. (9.5mm.); diameter, 0.2in. (5mm.). Hab. On stones and sand, covered with Algœ. South Island: Small creek from Governor's Bush (near Mount Cook Hermitage); Birch Hill Lagoon (seven miles from Hermitage). Under the influence of the atmosphere the organic part of the shell gets easily decomposed, and the shell becomes so fragile that it hardly can be touched without breaking. I think the water contains very little carbonate of lime. I give it the name of my son Alfred, who discovered this shell near Governor's Bush. Explanation of Plates XIV. and XV. Plate XIV. Fig. 1. a, b. Helix pseudoleioda. " c. Its aperture, showing disposition of lamellæ. Fig. 2. a, b, Helix wairarapa. " c. Its aperture, with lamellæ. Fig. 3. a, b. Helix hectori. " c. Its aperture, with lamellæ. Fig. 4. a, b. Helix microundulata. " c. Its aperture, and lamellæ. " d. Part of the shell, showing the ribs and brown streaks. Fig. 5. a, b. Helix aorangi. " c. Its aperture, and lamellæ. Fig. 6. a, b. Patula infecta, var. irregularis. Fig. 7. a, b. P. colensoi. Fig. 8. a, b. P. variecostata. " c. Showing the arrangement of the ribs. Fig. 9. a, b. Patula raricostata.

Plate XV. Fig. 10. a, b. Diplomphalus subantialba. Fig. 11. a, b. D. huttoni. Fig. 12. a, b. D. moussoni. Fig. 13. a, b. Hyalina microreticulata. Fig. 14. a, b. H. allochroida. " c. Part of the shell, showing the ribs and reticulated interstices. Fig. 15. a, b. Hyalina allochroida, var. sericata. Fig. 16. a, b. H. allochroida, var. lateumbilicata. Fig. 17. a. Limnœa alfredi.