Field Observations on the New Zealand Frog, Leiopelma Fitzinger

Transactions and Proceedings of the Royal Society of New Zealand, Volume 84, 1956-57, Page 867

Field Observations on the New Zealand Frog, Leiopelma Fitzinger By Elsie M. Stephenson and N. G. Stephenson [Received by Editor October 1, 1956.] Abstract A summarised account is given of published field observations of Leiopelma since its discovery in 1852. To this is added information obtained from the authors' field investigations of L. archeyi and L. hochstetteri, including such topics as range, habitat, feeding habits, colour pattern and life history. The taxonomic position of the genus and possible subspeciation of L. archeyi are discussed. A revised key for L. archeyi and L. hochstetteri is proposed. Initial experiments in assessing population numbers and pattern of distribution of L. archeyi are described, as also is a method used in artificial induction of egg-laying in the same species. Indications are given throughout of desirable directions for future study of the genus. Historical Introduction To A. S. Thomson, surgeon to the 58th Regiment, belongs the distinction of having written the first account of the New Zealand native frog (Thomson, 1853, 66). In October, 1852, gold was found in the hills surrounding Coromandel Harbour During the following month, Thomson visited the area and watched prospectors washing the soil of a mountain stream. During their excavations they displaced a number of boulders, under one of which they found a frog. Amid general excitement the unfortunate animal was placed by the men in a tightly-corked bottle, in which it soon died. It was then given to Thomson, who took it with him to a conference at which Lieutenant-Governor Wynyard was negotiating for gold-digging rights with the chiefs of local Maori tribes. The appearance of the frog greatly surprised the Maoris who, according to Thomson, had no word for it in their vocabulary. They regarded it with very great awe as being possibly the spirit or god of the gold. Later, three more frogs were found in another stream. One of these was lost and the Maoris insisted on the release of the other two in case supernatural vengeance should descend on the collectors. Although Thomson described the frog he did not name it. From his description it was clearly a specimen of what is now known as Leiopelma hochstetteri. The name Leiopelma was provided by Fitzinger (1861), who described two male frogs, both of the same species. These were collected from the Coromandel peninsula by the Austrian naturalist, Hochstetter, who had visited New Zealand during the course of his voyage in the frigate “Novara”. Fitzinger apparently had not read Thomson's paper: at least he made no comment on it. He regarded Leiopelma hochstetteri as being more closely related to Telmatobius peruvianus Wiegman—classed by Noble (1931, 499) as a bufonid—than to any other anuran then known. He placed the genus among the true “water frogs”. A translation of Fitzinger's Latin diagnosis of the genus and species is given below. The rest of his detailed description has been summarised by a later author (Steindachner, 1869). Character of Genus. Transverse processes of the sternum dilated. Parotoid glands absent. The soles of the feet devoid of hard pads and the joints of the fingers devoid of swellings. Fingers free, toes half-webbed. Males devoid of vocal sacs. Tongue free behind and a perfect oval. L. hochstetteri: Ashy-black, spotted below with white; the thighs speckled with white ventrally; dorsal surface of the thighs, tibiae and feet faintly banded with black; a white spot on each side of the palms of the hands and also beneath the inside digit of the foot.

It seems curious that Fitzinger should have mentioned a dilation of the sacral diapophyses. Compared with those of most anurans these structures in Leiopelma show only a slight distal flattening and dilation. Fitzinger's account makes it quite clear that the two frogs were found in water and that the only known locality was “the neighbourhood of the Coromandel Harbour on the East side of the Hauraki Gulf.” The frogs were collected for Hochstetter by the Maoris who, surprisingly enough, appeared to have overcome their initial fear. They were employed in panning for gold in “small creeks which spring from the Cape Colville Mountains and flow to the sea.” Fitzinger mentioned that one specimen of Leiopelma was in the British Museum at the time of publication of his paper in 1861. This specimen could either have been one of Hochstetter's two or, more likely, Thomson's original frog, which reached James Thomson, Esq., Glendoman, in 1853. The amphibian catalogue at the British Museum, however, states that a specimen of Leiopelma was first acquired in 1865, and that it was presented by “Sir A. Smith”. Through the courtesy of the Natural History Museum authorities E. M. Stephenson was permitted to examine this specimen in 1948, and was interested to find that the spelling of the name on the label was Liopelma. This spelling has been attributed to Günther (Turbott, 1942, 247) who, in 1868, published a short list of anurans added to the collection of the British Museum after 1858. Whatever the history of this particular specimen, Fitzinger's published name for the genus clearly predated that of Günther and the original spelling should be retained (Turbott, 1942, 247). In 1867, Hochstetter's own book on New Zealand appeared. A short paragraph in this emphasises the uniqueness of this frog, its rarity, and the fact that it was known to frequent only creeks and swamps of the Cape Colville Range. He accepted Fitzinger's classification. The year 1869 brought the publication of “Reise der Fregatte Novara. Zoologischer Theil.” by Steindachner. Leiopelma was not included amongst the many amphibian illustrations but was, however, reclassified by Steindachner and placed in the family Bombinatoridae. Steindachner also altered and improved Fitzinger's generic description and summarised the account of the specific characters. Hutton (1879) translated Steindachner's description In the account of the specific characters one reads “external nostrils rather nearer to the eye than to end of muzzle”. Compare this, however, with Fitzinger's original “Die Nasenlocher liegen genau in der Mitte zwischen den Augen und dem Schnauzenende”. In 1870, A. W. Aitken published a brief account of his finding of a frog in a range creek running through the Thames gold-field, near Puriri, at a height of at least 500 feet above sea-level. He did not describe the animal, but from its location it was presumably L. hochstetteri Fitzinger. Aitken's original specimen was sent to the Auckland Branch of the New Zealand Institute, but is apparently not in the Auckland Museum (Turbott, 1942, 251). The first discovery by a European of frogs on the hills, out of water, was made by S. Percy Smith, in 1862, but his findings were not recorded until 1921. The frogs were found under moss-covered stones on the crest of the main Coromandel Divide, and were described as being green and golden-brown in colour and about an inch long. As will be seen later, they belong to a subsequently described species, L. archeyi Turbott. In 1889, George Graham was shown native frogs on “the ridges of the Moehau ranges” by a Maori. Graham did not publish his observations until 1924, and then only as a note in a paper by John White on the Patu-paiarehe. According to Graham's Maori guide, the frogs of Moehau were incorporated in local legend as the sentries of the mysterious Patu-paiarehe. In 1898, McClaren published an account of the geology of Mt. Moehau. He mentioned Leiopelma and spoke of “. its singular mode of progression, its colour, and finally its many attitudes, so grotesquely human.…”

In 1919, McCulloch recorded the finding of a new species, Leiopelma hamiltoni McCulloch, on Stephens Island, in Cook Strait. The animal was clearly terrestrial, had only a faint trace of a web, and was patterned in green and brown. McCulloch placed the genus in the family Discoglossidae. The first published account of the development of any species of Leiopelma was written by Archey (1922). He visited the Tokatea ridge, a few miles north-east of the Coromandel township, during the breeding season (October-December) and collected eggs and frogs from under logs on the ridge, well away from surface water. Back in Auckland he watched the direct, intracapsular development of the embryos under a binocular microscope, and managed to keep a few specimens alive until they hatched. He also carried out a significant experiment (N. G. Stephenson, 1951 b, 20) by releasing one embryo from its capsule and allowing it to develop for some days in water. His valuable account dealt with external features only. Turbott (1942) was the first to recognise that the terrestrial frogs from Tokatea, which had been collected by Archey and which apparently resembled those recorded by Smith (1921) and Graham (1924), belonged to a third species of Leiopelma which he named Leiopelma archeyi. He published a diagnosis of this species and a key separating the three species of Leiopelma. He also summarised what was known of the distribution of the frog. Observations up to the time of publication of Turbott's paper had indicated that L. hochstetteri Fitzinger was dependent on the presence of surface water and was typically found only in streams, while L. archeyi Turbott was confined to adjacent ridges and hill tops. In other words, a material barrier was thought to exist between the two species at least in the breeding season when conditions are possibly fairly dry. Field observations by Stephenson and Thomas (1945) showed that the idea of a material barrier required qualification. During December, 1944, they found a specimen of L. archeyi and a specimen of L. hochstetteri, both females, under the same stone on the Tokatea ridge, well away from surface water. This close mingling of the two species was observed on other occasions also by the same authors, and it is now known that L. hochstetteri can be found at appreciable distances from streams. L. archeyi, on the other hand, has been found actually in stream water (Turbott, 1949). Vivarium specimens of L. archeyi, if provided with a pool of water, will often choose to sit in it (authors' observation). The existence of a material barrier of any geographical kind does not therefore hold, although the two species presumably have some type of mating barrier. They appear to be true sympatric species (Mayr, 1942) on the Coromandel Peninsula. In other regions, e.g., Huia, Warkworth and Karekare, L. hochstetteri occurs alone (Fig. 1, p. 871). Stephenson and Thomas (1945) also showed that the maximum body length proposed in Turbott's key (1942) was inadequate for L. archeyi Turbott, and that the majority of specimens found by them at Tokatea exceeded this. L. archeyi may reach a size of 41 mm, and 39 mm to 40 mm is not uncommon. An alternative key is published in another section of this paper. In November, 1946, N. G. Stephenson collected several egg clusters of L. archeyi from under stumps or logs on the sphagnum bog near the summit of Mt. Moehau, on the eastern aspect. He watched them develop under laboratory conditions, killing and fixing specimens at regular intervals, from intracapsular embryos to post-hatching stages, when the tail is reduced and adult proportions attained. Stephenson was able to make comparisons of the development of Leiopelma archeyi with that of Ascaphus truei and with amphibians having direct development (N. G. Stephenson, 1951b). He was also able to suggest an approximate time length for the entire developmental period. At that time, nothing was known of the life history of L. hochstetteri and L. hamiltoni.

In 1947, the authors were given permission by the Hon. Minister of Internal Affairs, Wellington, to collect a certain number of frogs for study in London. For this purpose specimens of both L. archeyi and L. hochstetteri were taken from Tokatea, Coromandel, and transported by ship, without any casualties, to England. The frogs were kept in damp moss inside large jars, and were housed in an anteroom to a main refrigerating chamber. En route they were fed on house-flies, and arrived in London in excellent condition. Most of them were eventually killed and used for anatomical study, but a few were kept alive in the Zoology Department, University College, London. They were eventually left in the care of the Curator of Reptiles and Amphibia at Regent's Park Zoo. In captivity, the frogs showed no inclination to breed, and after a time several attempts were made to induce ovulation, and possibly amplexus, artificially. These attempts to induce ovulation were successful and, as described in a later section, four batches of eggs were laid. This is the first record of Leiopelma eggs laid in captivity. Unfortunately all were infertile. Amplexus was not observed, nor has this been recorded so far in the field. A detailed study of the adult cranial characters of L. archeyi and L. hochstetteri (Elsie M. Stephenson, 1951) showed conclusively that at least eight constant, specific differences exist in these characters alone. In 1949, the question whether L. hochstetteri had direct development or whether it possessed an aquatic tadpole stage, was solved by Mr. S. Gittos, of Warkworth (Turbott, 1949). Mr. Gittos found egg capsules containing embryos in “wet mud of a seepage or spring” on his property on the slopes beneath the peak known as the “Dome”, a locality in which he had been observing the frogs over a period of some years. In November, 1949, Mr. E. G. Turbott, of the Auckland War Memorial Museum, accompanied Mr. Gittos to another forest-covered seepage, and found frogs and eggs in wet clay. Some were in tunnels made by dragonfly nymphs (Turbott, 1949, 375). The development of L. hochstetteri has since been described by N. G. Stephenson (1955) to whom these eggs were given by Mr. Turbott. Stephenson was able to show that eggs separated from the same cluster would undergo their intracapsular development equally well when immersed in water, as when placed in damp terrestrial situations. Since McCulloch's publication in 1919, little had been heard of L. hamiltoni McCulloch on Stephens Island, Cook Strait. Occasional specimens were found up to 1942 (Dawbin, 1950, 830), but from that time until 1950 even repeated searches for the frogs failed to locate them. It was concluded that the disappearance of the bush and the subsequent drying out due to strong winds and sunlight had caused the extinction of this species. The frogs had always been confined to a boulder bank at the top of the island, a region which by 1950 had lost its forest cover. Early that year, however, Mr. W. H. Dawbin, of Victoria University College, and Mr. R. Dawbin, found one frog. In May of the same year, five more were found, which were photographed and released. A few more specimens have been found by Mr. W. H. Dawbin on occasions since then. At the present time, no direct observations of developmental stages of L. hamiltoni have been made. Since no surface water occurs on the boulder bank, an intracapsular mode of development undoubtedly proceeds under sufficiently damp terrestrial conditions—probably deep under the boulders. By permission of the Hon. Minister for Internal Affairs, and through the kindness of Mr. W. H. Dawbin, E. M. Stephenson was given a specimen of L. hamiltoni in 1951, and later (1955) published an account of the cranial characters. L. hamiltoni resembles L. archeyi in many external characters, particularly in colouring, absence of a web, and presence of parotoid glands. It also resembles L. archeyi in five out of the eight cranial characters mentioned above as distinguishing L. archeyi and L. hochstetteri.

Distribution The accompanying map (Fig. I) indicates the distribution of the three species of Leiopelma as known at present. The areas in which the authors themselves have observed Leiopelma are indicated in the key; the other regions are from information obtained by Turbott (1942, 248). Altitude Typically, Leiopelma does not inhabit low-lying areas and has not been found by the authors below 400 feet above sea-level. At this height a small colony of L. hochstetteri inhabits a bush-covered stream near Karekare. At Workworth, L. hochstetteri may be found at 550 feet, while at Huia it occurs between 540 and 700 feet. On Mt. Moehau, L. hochstetteri is found in streams up to approximately the 2,500 feet level. Fig. 1.—Map of the North Island of New Zealand showing the known distribution of Leiopelma. Key to Symbols ▴L. hochstetteri. ▵L. archeyi. L. hamiltoni. • Areas studies by the authors.

L. archeyi has not been recorded below 750 feet (on ridges of Mt. Moehau) and extends there up to 2,958 feet at the summit. L. hamiltoni (Dawbin, 1950, 830) is found at a height of approximately 1,000 feet. Habitat In the localities where Leiopelma occurs, types of habitat can be distinguished as follows:— (a) Streams or creeks L. hochstetteri mainly, but L. archeyi (Turbott, 1949, 373), occasionally (b) Bush (forest), either close to or remote from streams L. archeyi and L. hochstetteri (c) Open country, away from streams L. archeyi, L. hamiltoni and occasionally L. hochstetteri (a) Streams or Creeks. Only L. hochstetteri is typically found in streams, and even with this species it is quite common to find frogs under stones on the banks instead of in the water. The distribution tends to be localised even within a single stream, the precise nature of the limiting factor being at present obscure. The type of stream favoured typically contains small waterfalls, cascades and potholes. Stones of all sizes are strewn over the bed, often accompanied by driftwood debris and covered with mosses and liverworts. The surface cover from the surrounding bush vegetation is usually considerable. Behind this marginal vegetation, the taller trees effectively screen out much of the light and help also in preventing air currents. Exceptions from this general rule, however, are known, and the authors on several occasions on Mt. Moehau found L. hochstetteri in parts of streams almost completely free from covering bush. The frogs are never found in deep water or in the direct path of a current, but prefer quieter reaches where stones are plentiful. Suitable stones for concealment are usually not less than six inches across and are generally flattened. As they lean against each other or against the bank, they form crevices in which the frogs can shelter. (b) Bush (forest), close to or remote from streams. Areas on the Tokatea Ridge, some 1,600 feet above sea level, and many regions on the slopes of Mt. Moehau, up to 2,000 feet provide excellent examples of this type of habitat. Included here also is the area near Warkworth where Messrs. Gittos and Turbott found frogs and eggs in wet clay close to a forested stream (Turbott, 1949, 375). Along the Cape Colville Range, northwards from the Tokatea saddle, bush occurs mainly on the eastern face. Here, in certain localised areas, frogs occur in large numbers. It is in one of these areas (Plate 58, Fig. 1), only a few yards in from the side of a logging track running along the top of the ridge, that specimens of L. hochstetteri were first found in association with L. archeyi (Stephenson and Thomas, 1945, 320). In wet weather temporary creeks may be found coursing down the slope from the ridge, but the nearest permanent stream is approximately half a mile below. Close to the top of the ridge the bush has a very open character, due partly to logging activities, with a sedge, Uncinia sp. in great abundance in the undergrowth. Logging in the region in question now appears to have ended, which is fortunate from the point of view of survival of the frogs. Much evidence of the activities of wild pigs is present, but there is little indication that they disturb the heavy stones under which Leiopelma shelters. Further in from the ridge top the bush becomes much denser in character (Plate 58, Fig. 2). Shade is provided by Tawa (Beilschmiedia tawa), Kohekohe (Dysoxylum spectabile), Mahoe (Melicytus ramiflorus), Kawakawa (Macropiper excelsum) and

Rangiora (Brachyglottis repanda). Tree ferns are plentiful and epiphytes of many kinds common. The latter include many of the moisture loving filmy ferns (Hymeno-phyllum spp.) and it is clear from these and other indications that the relative humidity is high. Mist is very common on the ridge, often lingering for days at a time. Most of the many stones on the forest floor are covered with mosses, ferns and lichens. Further down the slope the bush becomes an exasperating mass of thickly tangled, tough-stemmed supplejack (Rhipogonum scandens). As in the streams, the larger, more flattened stones are the most favoured by the frogs, and in each case they are set at an angle to the ground, to tree roots, or to other stones, so that crevices are provided. Beneath them are often found tangled roots and smaller stones. Over the crevices hang fern fronds, and they are fringed from below by ground plants. Obviously this screen of vegetation helps in moisture conservation and light elimination. On the forest-covered portions of the slopes of Mt. Moehau, the vegetation is more montane in character than at Tokatea and varies considerably in density (Moore and Cranwell, 1934; Cranwell & Moore, 1936). Stones are less common than in the Tokatea bush, and the frogs are typically found beneath or even inside decaying logs. (e) Open country, not associated with streams. The areas of open country which the authors have examined include the upper slopes and flat areas of the eastern aspect of Mt. Moehau (Plate 56, Fig. 2; Plate 57), and the grassy slopes near the top of the Tokatea Ridge. The latter mainly occur on the western face. The actual summit peak of Mt. Moehau is covered by a sub-alpine plant association but the extensive areas of open ground around it on the eastern side bear grasses and mosses and other low-growing plants, while lying everywhere are scattered stumps and logs (Plate 57). South-east from the peak and at a height of over 2,000 feet, is a flat, open, boggy area. Mosses are dominant here, especially the peat-forming Sphagnum sp., Eucamptodon inflatus, and several species of Dicranoloma. Conspicuous among them are two lichens, Cladonia retepora and C. floerkiana, while sedges (Gahnia spp.), rushes (Juncus sp.), and a number of ferns, including Blechnum minor, Gleichenia dicarpa and Paesia scaberula also flourish. Lycopodium fastigiatum and L. laterale are common. In summer, after a few days of hot, dry weather, helped by the strong winds, the ground quickly dries and hardens on the surface and the plants themselves give evidence of desiccation. Frequent mists and hanging cloud caps, however, help to negate the effects of drying by sun and wind, and the authors themselves have had unpleasant experience of the fact that a sudden storm can turn a hard baked ground into a squelching, waterlogged bog within a few hours; This condition probably persists through a good deal of the winter, and in this season also a light covering of snow has been known to occur on the peak. The rigorous and changing seasonal conditions on Mt. Moehau make the need of effective shelter imperative for any anuran. Leiopelma archeyi finds this in the dark, still, moist spaces beneath large boulders and stones, in the crevices of decaying tree stumps and fallen logs, and, more temporarily, among clumps of sedges and grasses. As in other localities, the boulders are fringed by plants which act as screens against light and too severe desiccation. The open country on the Tokatea Ridge consists of grassland which has arisen by clearing and burning of bush. Scattered logs lie among the grass and bracken and surface water is normally absent. Frogs are not numerous, but specimens of L. archeyi and an occasional L. hochstetteri may be found under the logs. As on Mt. Moehau, the prevalent mists presumably play an important part in making such a habitat possible.

Food and Feeding Habits Turbot (1942, 250) indicated that L. hochstetteri feeds nocturnally away from the stream beds. He discovered in the stomach of one frog “the shell of a small, flat-spired gasteropod and portion of an arthropod appendage, probably of the terrestrial genus Parorchestia… both food organisms inhabiting leaf-mould bordering on the stream bed.” In 1946, the authors discovered in the stomach of a stream-dwelling L. hochstetteri a small but entire fresh-water crayfish, suggesting that L. hochstetteri may also catch part of its food in the water. The stomach contents of the few other frogs examined have included small dragon-flies, shells of Sphaerium, an unidentified beetle larva, and various adult beetles. From the undigested parts of beetles found in the gut of a specimen of L. archeyi, Dr. E. B. Britton, of the British Museum of Natural History, was able to identify a Dascillid of the genus Cyphanus, probably Cyphanus medius Broun. The stones and logs under which Leiopelma shelters harbour a rich invertebrate fauna including beetles, ants, millipedes, earthworms and spiders. From the few specimens of Leiopelma of which it has been possible to examine the gut contents, it seems that beetles of various types predominate as food, but that the frogs are capable of enjoying a mixed diet. This probably explains why so little difficulty was experienced in feeding vivarium specimens. E. M. Stephenson found that both L. archeyi and L. hochstetteri remained extremely healthy on a diet of house-flies or blow-flies, but that they were not very adept at catching quick-flying insects and required to be more or less hand-fed. The technique employed was to place a number of flies in a jar covered with muslin and to moisten the covering pad with ether. The moment the flies had succumbed they were transferred to a flat stone in the frog cage. There, as they began to show signs of movement, they were quickly seized by the frogs. Even specimens of Leiopelma about 33 mm in body length could on occasions eat four or five house-flies in one day but were by no means always hungry enough to do so. They fed most readily in a dim light. It was found that the frogs would eat fly larvae if sufficiently hungry, but appeared to find difficulty in swallowing them. During the capture of food and its subsequent swallowing, the tongue, which appears to be attached relatively further back than in Rana and is oval or rounded in shape, seems less efficient than in the latter genus. Added importance appears to be given by Leiopelma to body movements, especially those of the head and shoulders. Parasites At least two kinds of intestinal parasites occur in Leiopelma. Specimens of L. hochstetteri from Huia and Tokatea, and L. archeyi from Tokatea and Moehau, have been infested with nematodes in the intestine. A few specimens of these, unfortunately all female, were sent to Dr. Bayliss, of the British Museum of Natural History. He referred them to two species of Oxyuridae (Cosmocerinae), possibly Aplectona, but in the absence of males could carry the identification no further. In two specimens of L. archeyi from Tokatea only, a trematode was found in the large intestine. The specimens sent to Dr. Bayliss were not in sufficiently good condition for identification, but possibly represent a new species of Opisthioglyphe. The life history of this parasite is unknown. Colour The colour pattern in Leiopelma appears to be constant for each individual frog. Each vivarium specimen could be clearly recognised from the others by its colouration, while during two years in captivity no frog changed perceptibly in colour.

Fig. 1.—The southern peak of Mt Mochau In the foreground is a flat boggy area above the bush-line on the south-eastern face. The actual summit peak is to the right of the photograph. Fig. 2.—The sphagnum bog area, looking eastward Many frogs are found under the boulders and stumps.

Fig. 1—Looking from the summit eastward down the slope towards Stony Bay Fig. 2.—Further down the same slope Adults and eggs of L. archeyi are found under the many fallen logs and stumps

Fig. 1.—A. patch of bush on the eastern face of the Tokatea Ridge, north of the saddle L. archeyi and L. hochstetten were first discovered together here in 1944 Fig. 2.—The interior of the same bush The frogs are found beneath stones on the forest floor The tough stems of supplejack are conspicuous.

Fig 1.—L. hochstetten, × 3 (Neg Mr. W. Brackenbury). Fig. 2.—An egg cluster of L. archeyi, photographed in the field The covering stump has been pulled away and the eggs lie exposed on a bed of earth and rotting wood in the centre of the photograph Fig. 3.—Eggs of L. archeyi. laid in the laboratory after an injection of anterior pituitary from Rana × 7 (Neg the late Mr. F. J. Pittock FRPS)

The process of sloughing, which in some frogs is so marked that the skin can be seen flaking off in large patches, has not been observed by the authors in Lelopelma and presumably is an inconspicuous process. The dorsal colour patterns of a large number of specimens of L. archeyi have been observed in the field, both on the Tokatea Ridge and Mt. Moehau. The animals can be placed in a graded series ranging from brown frogs with little or no trace of green, through specimens which have green and brown intermingled, to predominantly green frogs in which brown is scarcely visible or even absent. The shades of brown range from a deep chocolate to brownish-yellow or biscuit, while the greens vary from emerald to an almost bluish-green. It has been found, however, that it is possible to fit the various types of colour pattern to the following key:— a = predominantly green. b = predominantly light brown. c = predominantly dark brown. ab = green and light brown, green predominating. ba = light brown and green, light brown predominating. ac = green and dark brown, green predominating. ca = dark brown and green, dark brown predominating. Turbott's holotype (1942, 249) would fit the description ba above. In addition to the colours described above, each frog has a dorsal pattern of black markings and a ventral body colour resembling Turbott's description. L. hochstetteri (Plate 59, Fig. 1) is predominantly brown in dorsal body colour, but here again the exact shade may vary. It is usually darker than that of L. archeyi, being typically a blackish-brown, but occasional specimens show decided olive-green or biscuit tints. The black bands are inconspicuous in dark specimens of L. hochstetteri. Colouration in Relation to Concealment In both L. hochstetteri and L. archeyi, the almost invariable first reaction of a frog to the removal of a covering log or stone is to remain perfectly still. After a time, however, it leaps suddenly to a darker spot. This movement is apparently mainly a reaction to light and, possibly, desiccation. It has been shown (Czopek, 1955, 357) that in L. hochstetteri at any rate, the skin capillaries are very much more important than the lungs in effecting gaseous exchange. Because of their initial immobility, specimens of Leiopelma are sometimes difficult to recognise, and this is especially the case with L. hochstetteri when it is found in a stream. With its colouring resembling that of the gravel and mud, and in its typical, flattened, crouching position, with its angular head merely lifted to free the nostrils and eyes from the water, it can easily be overlooked when one is searching in the shaded stream bed. If, however, it is accidentally touched, the frog quickly discloses its presence by leaping away. On brown earth, under the same log, specimens of L. archeyi of all types of colour pattern (Table I) may be found together. The colour patterns of different specimens of L. archeyi do not therefore appear to be adapted to the individual environment except that L. archeyi, and to some extent lighter-coloured specimens of L. hochstetteri, show a type of disruptive colour pattern which Cott (1940) has called “coincident disruptive colouration”. If the hind limbs are considered in relationship to the normal crouching attitude of rest (E. M. Stephenson, 1955, Pl. I), it is seen that the oblique black bands on the parts of the hind limb coalesce—i.e., when the leg is folded up the dark bands on the thighs mainly coincide with those on the leg, the latter forming in turn a continuation of those on the foot. Also, the bands on the thighs often form a continuation of black patches on the sides of the body. This type of pattern accentuates a superimposed structure, built up by black bands, passing across the true structure, which is made less obvious.

The black markings at the sides of the snout and eyes, the bands on the fore limbs, the broken bands of the dorso-lateral ridges, are the components of other types of disruptive pattern. The value of concealing colouration to an animal which by daylight lies hidden beneath heavy objects such as large stones and logs, seems difficult to assess. Voice Leiopelma has no voice in the true sense. Occasionally, when specimens of L. archeyi are disturbed, they produce successive, shrill, “chirping” sounds, the mouth being opened widely at each cry. Repetition of the sound can often be induced by a touch. This type of cry is by no means unusual in anurans. Noble (1931, 409) points out that a scream or a squeal is a common response when various types of frogs are pinched or startled, and that the lungs are only partly deflated at each note. Lack of a normal call in Leiopelma eliminates the possibility that different mating calls could prevent interbreeding between L. hochstetteri and L. archeyi where they overlap in range. N. G. Stephenson (1951 a, 247) has already expressed the view that the absence in urodeles and in the primitive frogs Leiopelma and Ascaphus of certain middle ear structures and of a voice may be considered as a primary feature instead of representing a secondary loss. Movement When moving over the ground Leiopelma progresses in a series of short leaps, rarely more than a foot long. In water, L. hochstetteri swims with a characteristic alternate action of the hind-limbs (Turbott, 1942, 250). The fore limbs are typically held motionless in a forward direction, except for occasional paddling movements. Specimens of L. archeyi also swim when placed in water but tend to tire quickly and come to rest (authors' observations). Tonic Immobility Leiopelma shows the common anuran reflex known as “tonic immobility” (Noble, 1931, 424). When specimens are picked up in the field they occasionally become quite rigid, sometimes remaining in this condition for several minutes. The same reaction can usually be induced by causing a frog to lie on its back in one's hand for a few seconds. Quite often, a light touch will then induce the immobile frog to spring suddenly back to its normal position. It is apparently due to an hypnotic effect (Mangold, 1925) produced by a tactile stimulus, and helped, probably, by the warmth of the hand. Possibly it has a protective value. Summary of the Life History and Breeding Habits Leiopelma archeyi lays eggs in the spring, and the time taken from egg laying to hatching is at least six weeks (N. G. Stephenson, 1951 b, 20). The number of eggs in each cluster varies from two to eight. Each is enclosed in a gelatinous capsule, is heavily yolked, unpigmented, and measures 4–5 mm in diameter. There is no covering envelope for the whole cluster as Archey (1922) at first thought, but each egg adheres to the others by means of its own capsule, which is initially sticky. When development is sufficiently advanced, a light touch on the wall of the capsule will cause the enclosed embryo to rotate vigorously. Hatching, which was observed by the authors in December, 1944, and December and January, 1946, is accomplished partly by the muscular action of the tail, which rotates vigorously and emerges first, and partly by the disintegrating action of numerous small glands in the skin of the head and along the back. These glands are present in intracapsular stages but disappear at hatching (N. G. Stephenson, 1951 b, 22).

Four weeks after hatching the tail has practically disappeared, while appreciable quantities of yolk still remain. The young frogs are recognisable as specimens of L. archeyi very early by the presence of parotoid glands. The eggs are laid beneath logs or in rotting stumps (Plate 59, Fig. 2), often surrounded by a moisture-conserving mixture of decaying wood, leaf mould and soil. They are always protected from light. Archey (1922) recorded several instances of a frog sitting over a cluster of eggs, but owing to an accident to his specimens he was unable to decide the sex of the animals in question. The authors have since found several frogs crouching over egg clusters on Mt. Moehau, and proved these in each case to be males. As amplexus has not been recorded for any species of Leiopelma it is not yet known whether fertilisation is internal or external. Ascaphus truei has internal fertilisation, but in this genus the male has a unique and specialised intromittent organ. On the other hand, Nectophrynoides, an ovoviviparous African toad (Noble, 1931, 15) achieves internal fertilisation without the aid of special copulatory organs. The presence of a male Leiopelma archeyi in association with a group of eggs (usually a cluster not far advanced in development) may possibly be an example of the so-called “brooding” habit shown by a few amphibians (Noble, 1931, 413), or it may have the function of ensuring external fertilisation. Possible support to the latter view is given by the fact that not all the eggs in a cluster are usually at quite the same stage of development, and that infertile eggs are fairly common. Yet another alternative is that the adult frog may provide moisture for the egg by means of urinary excretion, as may possibly be the case with the Australian toad Chiroleptes platycephalus (Needham, 1942). The eggs appear to be long in maturing, for well-developed ova have been found in an ovary even in the winter. It seems probable, from the examination of a very limited number of specimens, and from artificially induced ovulation, that each female lays at least two clusters of eggs each season, one from each ovary. The oviducts have wide anterior funnels and enlarge posteriorly into thinner-walled regions which may be regarded as ovisacs. These unite together in the middle line to form a median “uterus” which opens into the cloaca. A similar structure is found in Bufo, Alytes and Nectophrynoides (Noble, 1931, 273). Vestigial Müllerian ducts are invariably present in the males, uniting together anteriorly to the cloaca in the same way as the oviducts of the females. As has been mentioned above, E. M. Stephenson made sveeral attempts to induce egg-laying in L. archeyi and L. hochstetteri. A few specimens were on several occasions injected with a gonadotrophic hormone preparation, Pregnyl, which in certain other anurans—e.g., Xenopus, readily induces ovulation and pairing. In spite of varied dosage, this treatment had no apparent effect on any of the specimens of Leiopelma involved. In 1948, small quantities of fresh anterior pituitary from female specimens of Rana temporaria, crushed in 1/10th Holtfreter solution (modification of method of Hamburger, 1942, 32) were injected into three specimens of L. archeyi and one specimen of L. hochstetteri. Implantation of fresh anterior pituitary substance had previously induced egg-laying and amplexus in Ascaphus (Noble & Putnam, 1931). Five days later, one female specimen of L. archeyi thus treated laid a cluster of five eggs (Plate 59, Fig. 3), followed by a further two eggs a week later. A second female of the same species which had been injected at the same time as the first, laid two eggs a month after injection and a single egg a few days later. The third specimen of L. archeyi was a male, and showed no reaction to the injection. The eggs were all infertile. Mr. S. Gittos' discovery (Turbott, 1949, 374) of the eggs of L. hochstetteri, and further description of these by Turbott (1949, 375) and N. G. Stephenson.

(1955) put an end to any speculation that L. hochstetteri might have had a free-living aquatic tadpole stage. Although frogs were observed in the vicinity of eggs found in wet clay tunnels adjacent to a stream, none of these was actually sitting over the eggs. The two clusters of eggs collected consisted of 10 and 11 eggs respectively. Possible Sub-speciation of L. archeyi in the Coromandel Peninsula The body lengths of 42 specimens of L. archeyi from open areas near the summit of Mt. Moehau (Plate 57, Figs. 1 and 2) and 21 specimens of L. archeyi from a patch of bush on the eastern face of the Tokatea Ridge (Plate 58, Figs. 1 and 2) were measured and compared. The figures were not selected but represented total counts on particular occasions. On Mt. Moehau the body lengths ranged from 19 mm to 34 mm, while on Tokatea they varied from 28 mm to 41 mm. The suggestion obvious in the figures—i.e., that the frogs on Mt. Moehau are typically smaller than those on Tokatea, seemed a sufficient basis for examining the measurements statistically, inadequate though the actual numbers of figures were. A standard t-test and an Aspin Welch test were applied, with quite similar results, both providing strong evidence for the view that the samples came from populations with different means. It is felt that the explanation of these results is to be found in sub-speciation, which could well have occurred in these isolated populations. Different environmental factors, for example, exposure on Mt. Moehau and protection by bush on Tokatea may also be significant, and in addition nothing is known of the relative merits of the diets available in the two areas. So far no detailed anatomical comparisons have been made between the frogs inhabiting the two areas. Only seven specimens of L. archeyi from open grassy areas on the Tokatea Ridge have been measured, and the highest figure for these was 35 mm.* E. M. Stephenson has subsequently revisited Mt. Moehau (January, 1957). On this occasion nine specimens of T. archeyi from forested areas on Mt. Moehau were measured, and the maximum body length was found to be 33 mm. This appears to lend further weight to the possibility of subspeciation in the Moehau and Tokatea areas. Population Counts of L. archeyi on Mt. Moehau In January, 1956, the authors endeavoured to obtain some idea of the density and pattern of distribution of the population of L. archeyi inhabiting the open, eastern slopes below the summit of Mt. Moehau (Plate 57, Figs. 1 and 2). A light rope, 20 yards long, which could be staked in position at each end, was used to mark out the quadrats, the directions of which were obtained by compass. The area one yard on each side of the rope was carefully combed for frogs, the same four searchers taking part in each count All movable logs and stumps were lifted, and all vegetation carefully examined. Findings for each side of the rope were recorded separately in terms of body lengths, numbers and groupings of frogs, and colour patterns. The results of these tentative investigations, excluding body lengths, are shown in Table I. From a mathematical point of view they are extremely inadequate, and it is hoped that further field work will remedy their deficiencies. Unfortunately the time taken to examine an area of even 20 square yards with maximum care and to record necessary observations is considerable. In addition, access to the summit of Mt. Moehau is relatively tedious and weather fluctuations inhibit continuous fieldwork. From the few figures available in Table I, however, it is possible to make some general observations: (i) The frogs are clearly grouped in colonies.

Table I.—Distribution of Leiopelma archeyi On MT. Moehau. Count No. Direction No. of Individuals Colour Patterns* For key to colour pattern see above. Area Covered 1 N.S. 0 20 sq. yds. 2 N.S. 0 20 sq. yds. 3 E.W. 4 + 1 = 5 ab, b, ba, 2ca. 20 sq. yds. 4 E.W. 5 a, ab, 2b, c. 20 sq. yds. 5 N.S. 1 b. 20 sq. yds. 6 N.S. 2 ab, ac 20 sq. yds. 7 E.W. 1 + 5 = 6 ab, b, 2c, 2ca. 20 sq. yds. 8 E.W. 4 a, b, 2c. 20 sq. yds. 9 N.S. 2 ba, c. 20 sq. yds. 10 N.S. 0 20 sq. yds. 11 E.W. 4 a, ab, b, c. 20 sq. yds. 12 E.W. 0 20 sq. yds 13 N.S. 0 20 sq. yds 14 N.S. 3 a, ab, b. 20 sq. yds 15 E.W. 4 ab, b, 2c. 20 sq. yds. 16 E.W. 2 + 2 = 4 2ab, b, ba 20 sq. yds. Total: Total: Total Area: = 40 frogs 4a = 320 sq. yds. = 14 colonies 10b 9c 9ab 3ba 1ac 4ca (ii) The obvious means are 2.50 frogs per quadrat (or unit area of 20 square yards, 2.86 frogs per colony, and 0.875 colonies per quadrat. The distribution of the frogs was examined from the standpoint of a colonial grouping. A Poisson distribution, as might perhaps be expected, did not fit these data at all well. A Neyman Type A contagious distribution (Skellam, 1955, 96) was tried (roughly allowing for the fact that having found one frog the probability of finding another frog in the quadrat was rather higher), but although the goodness of fit appeared to be satisfactory the actual figures obtained do not at the moment appear to be of much relevance. It is possible that they can be correlated with egg clusters laid in a certain area from which frogs reach a particular quadrat, but more data are necessary before really useful results can be obtained. No counts of this kind have so far been carried out during the breeding season. It should be emphasised that almost nothing is known of the movements of L. archeyi from place to place. Marking experiments would undoubtedly be valuable in this connection. Taxonomic Position of Leiopelma Noble (1922) referred Leiopelma and its North American relative, Ascaphus truei Stejneger to the family Discoglossidae. In 1924, however, he proposed a new family, the “Liopelmidae” to include Leiopelma and Ascaphus. In 1931, he placed this family in a separate sub-order Amphicoela at the base of his anuran classification. He justified this arrangement by the fact that Leiopelma and Ascaphus are the only living genera of frogs to possess amphicoelous vertebrae and that they retain two tail-wagging muscles, the pyriformis and the caudali-pubo-ischiotibialis, even though neither genus possesses a tail in the adult stage. Noble's recognition of the primitive character of Leiopelma has been supported by more recent anatomical studies, including work on the cranial morphology (Wagner, 1934 b; E. M. Stephenson, 1951, 1955); the circulatory system (E. M. & N. G. Stephenson, 1947; H. Szarski, 1951); development (N. G. Stephenson, 1951 a, 1951 b, 1955); the skeleton.

(Stadtmüller, 1924; Trewavas, 1933; de Vos, 1938; E. M. Stephenson, 1952; Ritland, 1955). The familial name Ascaphidae Féjévary 1923, as originally defined contained only Ascaphus truei Stejneger 1897, and predates Noble's Liopelmidae (1924), which contained both Liopelma Günther 1868 laps. cal. = Leiopelma Fitzinger 1861 and Ascaphus Stejneger 1897. Noble (1924), however, stated in a footnote that he followed present day custom in using the oldest generic name in forming the family name. N. G. Stephenson (1951 b, 18) pointed out that in deriving the familial name Noble formed it wrongly from the root and that its more correct form, which would also incorporate the original spelling of Fitzinger (1861), would be Leiopelmatidae. The present weight of knowledge of the two genera suggests to the authors that a further step, the separation of Noble's sub-order Amphicoela (Noble, 1931, 485) into two families, Leiopelmatidae (Type Genus: Leiopelma Fitzinger, 1861) and Ascaphidae (Type Genus: Ascaphus Stejneger 1897), would be desirable. Discussion of the anatomical details leading to this proposal is, however, outside the scope of the present paper. Key Separating L. archeyi And L. hochstetteri The following key is amended from that of Turbott (1942, 250) L. hochstetteri Parotoid glands absent. Toes half-webbed. L. archeyi Parotoid glands present. Webs absent or greatly reduced. Maximum size 41 mm. Size is no longer a clear distinction between L. archeyi and L. hamiltoni (Stephenson & Thomas, 1945, 320). The latter also possesses parotoid glands and has greatly reduced webs. The only other external distinction so far recorded between these two species appears to be the position of the nostrils relative to the tip of the snout and the eye (Turbott, 1942, 250). Conclusions The genus Leiopelma Fitzinger has attracted much attention in more recent years because of its primitiveness, but so far research has been confined largely to adult and developmental morphology. In presenting data covering a range of ecological, developmental and taxonomic topics, the authors emphasise the preliminary nature of their investigations in these fields. Many questions still remain to be answered, although a solution to some of them might well be expected if field studies can be continued. Other problems, involving relationships in time and space are still more elusive of solution. Presumably Leiopelma reached New Zealand during the Cretaceous period (Fleming, 1949, 75) but as Turbott (1949, 376) has pointed out, geological evidence so far available does not adequately explain the history and distribution of the species within New Zealand. No sufficient explanation has yet been offered for the survival of only two amphicoelous genera of frogs; the one, Leiopelma, in New Zealand; the other, Ascaphus, in North America; nor have the affinities of these two genera to each other, or to anurans in general, been satisfactorily defined. Acknowledgments The field work upon which this paper is based was begun at the end of 1944, when one of the authors was carrying out research for a M.Sc. degree in the Zoology Department of Auckland University College, and was continued at intervals until 1947. In December, 1955, and January, 1956, the Coromandel areas were revisited. The authors wish to acknowledge with thanks the help afforded by the following:

The Hon. Minister for Internal Affairs, Wellington, for permission to collect specimens of Leiopelma on various occasions. Mr. F. Rogers, M.A., for his company, and assistance on numerous field trips. Miss E. Bartley and Mr. R. Bartley, of Port Charles, for assistance in field work on Mt. Moehau in January, 1956. Mr. E. G. Turbott, M.Sc., of the Auckland War Memorial Museum, for helpful discussion and criticism. Members of the Auckland War Memorial Museum staff for identifying a number of plants found on Mt. Moehau. Mr. J. B. Douglas, M.A., B.Sc., Dip. Ed., Department of Mathematics, N.S.W. University of Technology, for carrying out statistical calculations and for preparing a report. Mr. P. D. F. Mumby, Department of Biological Sciences, N.S.W. University of Technology, for the preparation of prints from our negatives. References Adams, J., 1888. On the Botany of Te Moehau Mountain, Cape Colville. Trans. N.Z. Inst., 21, pp. 32–41. Aitken, A. W., 1870. On the New Zealand Frog (Liopelma hochstetteri) with an account of a remarkable feature in the history of some species of Australian frogs. Trans. N.Z. Inst., 2, pp. 87–88. Archey, G., 1922. The Habitat and Life History of Liopelma hochstetteri. Rec. Canterbury (N.Z.) Mus., 2, pp. 59–71. Cott, H. B., 1940. Adaptive Coloration in Animals. London: Methuen. Cranwell, L. M., and Moore, L. B., 1936. The Occurrence of Kauri in Montane Forest on Te Moehau. N.Z. J. Sci. Tech., 18, pp. 531–543. Czopek, J., 1955. Vascularization of respiratory surfaces in Leiopelma hochstetteri Fitzinger and Xenopus laevis Daudin. Acta anat., 25, pp. 346–360. Dawbin, W. H., 1950. The Stephens Island Frog. The Illustrated London News, 217, pp. 830–831. Fejervary, G. J. De, 1923. Ascaphidae, a new family of tailless Batrachians. Ann. hist.-nat. Mus. hung., 20, p. 178. Fitzinger, L. J., 1861. Eine neue Batrachier-Gattung aus New-Seeland. Verh. zool.-bot. Ges. Wien, II, p. 217. Fleming, C. A., 1949. The Geological History of New Zealand. Tuatara, 2, pp. 72–90. Graham, G., 1924. Note in “The Patu-Paiarehe” by John White. J. Polynesian Soc., 33, pp. 210–211. Gunther, A., 1888. First account of spp. of Tailless Batrachiens added to the collection of the British Museum. Proc. zool. Soc. Lond., pp. 478–490. Hamburger, V., 1942. A Manual of Experimental Embryology. Chicago: University Press. Hochstetter, F. Von, 1867. New Zealand. Stuttgart. Hutton, F. W., 1879. On the New Zealand Frog. Translated from the Zoology of the Voyage of the Novara (Fitzinger). Trans. N.Z. Inst., 12, pp. 250–251. McClaren, J. M., 1898. On the Geology of Te Moehau Trans. N.Z. Inst., 31, pp. 494–498. McCulloch, A. R., 1919. A New Discoglossid Frog from New Zealand. Trans. N.Z. Inst., 51, pp. 447–449. Mangold, E., 1925. Methodik der Versuche über tierische Hypnose. Abderhaldens Handb. biol. Arbeitsmeth., 6, pp. 320–368. Mayr, E., 1942. Systematics and the Origin of Species. New York: Columbia University Press. Moore, L. B., and Cranwell, L. M., 1934. Induced Dominance of Microlaena avenacea (Raoul) Hook. f. in a N. Z. Rain-forest Area. Rec. Auck. Inst. Mus., I, p. 219. Needham, J., 1942. Biochemistry and Morphogenesis Cambridge: University Press. Noble, G. K., 1922. The Phytogeny of the Salientia. I. The Osteology and the Thigh Musculature; their bearing on Classification and Phylogeny. Bull. Amer. Mus. Nat. Hist, 46, pp. 1–87. —— 1924. A New Spadefoot Toad from the Oligocene of Mongolia. Amer Mus. Novit., 132, p. 9. —— 1931. The Biology of the Amphibia. New York: McGraw-Hill. Noble, G. K., and Putnam, P. G, 1931. Observations on the Life History of Ascaphus truei Stejneger. Copeia, 3, pp. 97–101. Ritland, R. M., 1955. Studies on the post-cranial morphology of Ascaphus truei. I. Skeleton and spinal nerves. J. Morph., 97, pp. 119–178. Skellam, J. G., 1955. Quadrat Sampling from the Mathematical Standpoint. Proc Linn Soc. Lond., 165, pp. 95–102.

Stadtmuller, F., 1936. Das Os Parahyoideum (Fuchs) bei Liopelma hochstetteri und Rhinophrynus dorsalis mit Bemerkungen über den gesamten Zungenbein-Kehlkopf-Apparat dieser seltenen Froschlurche. Morph. Jb., 78, pp. 1–35. Smith, S. P., 1921. Letter in N.Z. J. Sci. Tech., 3, p. 308. (With note by J. Allan Thomson). Steindachner, F., 1869. Reise der Fregatte Novara. Zoologischer Theil, Vol. 1, Amphib., p. 33. Stephenson, Elsie M., and N. G., 1947. On the circulatory system of Leiopelma hochstetteri, with particular reference to the posterior cardinal veins and to the bloodvessels of the kidneys. Trans. Roy. Soc. N.Z., 76, pp. 492–503. Stephenson, Elsie M., 1951. The Anatomy of the Head of the New Zealand frog, Leiopelma. Trans. Zool. Soc. Lond., 27, pp. 255–305. —— 1952. The Vertebral Column and Appendicular Skeleton of Leiopelma hochstetteri Fitzinger. Trans. Roy. Soc. N.Z., 79, pp. 601–613. —— 1955. The Head of the Frog, Leiopelma hamiltoni McCulloch. Proc. Zool. Soc. Lond., 124, pp. 797–801. Stephenson, N. G., and Thomas, E. M., 1945. A Note Concerning the Occurrence and Life History of Leiopelma Fitzinger. Trans. Roy. Soc. N.Z., 75, pp. 319–320. Stephenson, N. G., 1951a. On the Development of the Chondrocranium and Visceral Arches of Leiopelma archeyi. Trans. Zool. Soc. Lond., 27, pp. 203–253. —— 1951b. Observations on the Development of the Amphicoelous Frogs, Leiopelma and Ascaphus. J. Linn. Soc. (zool.), 42, pp. 18–28. —— 1955. On the Development of the Frog, Leiopelma hochstetteri Fitzinger. Proc. Zool. Soc. Lond., 124, pp. 785–795. Szarski, H., 1951. Remarks on the blood-vascular system of the frog, Leiopelma hochstetteri Fitzinger. Trans. Roy. Soc. N.Z., 79, pp. 140–147. Thomson, A. S., 1853. On the Discovery of a Frog in New Zealand. Edin. New Philos. Journ, 55, pp. 66–69. Reprinted 1920 in N.Z. J. Sci. Tech., 3, pp. 220–222. Trewavas, E., 1933. The Hyoid and Larynx of the Anura. Philos. Trans. B., 222, pp. 401–527. Turbott, E. G., 1942. The Distribution of the Genus Leiopelma in New Zealand, with a description of a New Species. Trans. Roy. Soc. N.Z., 71, pp. 247–253. —— 1949. Discovery of the Breeding Habits of Leiopelma hochstetteri Fitzinger. Rec. Auck. Inst. Mus., 3, pp. 373–376. De Vos, C. M., 1938. Studies on the Liopelmidae. I. The Zonal and sternal skeleton of the Liopelmidae (Anura). II. The Inscriptional ribs of Liopelma and their bearing upon the problem of abdominal ribs in Vertebrata. Anat. Anz., 87, pp. 54–101. Wagner, D. S., 1934b. Liopelma Studies, No. 2. On the cranial characters of Liopelma hochstetteri. Anat. Anz., 79, pp. 65–77. Williams, T. W., 1941. Alizarin Red S and Toluidine Blue for differentiating adult or embryonic bone or cartilage. Stain. Tech., 16, pp. 23–25. Dr. Elsie M. Stephenson, Department of Biological Sciences, N.S.W. University of Technology, Broadway, Sydney, New South Wales. Dr. N. G. Stephenson, Department of Zoology, University of Sydney, Sydney, New South Wales.