EL | ALLE NG Pts el LOL tale NAL EN AEE I ALD ALL ALA LALA LLL. LOLA AL AL AL GA A A ELON LALO NLL Le LOLA AL cep iy gl Ne inti, mtnenty ‘ aa - ys! Sh eel oer Ee 9 IER ROY REIN IO NE POE AR NO i ct iS te OE OE EN NN ENTS EE Ae AM betinpatntinthnherte determines ra A ihe yetret Sa A ieiinn al Anan nue beabeibeaianden imate ee jogull hahateetotngat etn t= tenet d-tatnint al inpatahodagsdtutntn npn bateBetingetninentn tine masbeine ceatedim whe) oe tee ee at wegiiar eve hy wimrehe aloe whe wh m ie » \y! lagi ebeNREI wheme- 5 ¥i ng RECORDS of the INDIAN MUSEUM Vol. XX. A MONOGRAPH OF THE SOUTH ASIAN, PAPUAN, MELANESIAN AND AUSTRALIAN FROGS OF THE GENUS RANA. By Gen SOURENGER, LL.D. Disc... F.R-2.- Calcutta : PUBLISHED BY THE DIRECTOR, ZOOLOGICAL SURVEY OF INDIA. PRINTED AT THE BAPTIST MISSION PRESS. JUNE, 1920. A MONOGRAPH’ OF THE SOUTH ASIAN, PAPUAN, MELANESIAN AND AUSTRA- WAN FROGS OF THE GENUS RANA. By G. A. BOULENGER, LL.D., D.Sc., F.R.S., etc. (Published by permission of the Trustees of the British Museum), The species of the large genus Rana, now about 195 in num- ber,? have long been in need of a thorough revision. In the following pages I propose to deal with those inhabiting the Indo- Malay Region, or rather Southern Asia, to which I have added the few which extend the range of the genus to the Papuan and Melanesian islands and the extreme north of Australia (Cape York). I have taken as the northern and western limit of the area dealt with a line drawn from Palestine through Northern Persia, the Hindoo-Coosh (Hindu Kush) and Karakorum mountains to and including the Yang-tse-Kiang, a limit answering better the requirements of a survey of the distribution of Tailless Batrachians than those usually adopted for other groups of animals. The collection of the British Museum has greatly increased of late and affords ample material for the study I have undertaken ; in addition to this I have received much help from Dr. Annandale, both in material and in discussing some knotty points in con- nexion with Indian species. My grateful thanks are due to him. I therefore hope and trust the detailed descriptions I have drawn up, making use of several characters hitherto neglected, will prove of lasting value for the better understanding of the species, and of their inter-relationships. The description of Frogs is much more difficult than that of Reptiles, the naked skin depriv- ing us of the aid derived from the proportions and disposition of the shields and scales and their numerical characters; measure- ments of the different parts of the body are of first importance, and I have therefore prepared tables of very numerous adult or half-grown specimens, in order to convey exact information on this point, and also to show the amount of individual variation, a matter of great importance which is so often passed over. ! At Dr. Boulenger’s request I have added notes on the habits, geographical range, etc., of species with which I am personally acquainted. These notes are enclosed in square brackets and initialled. NM. Annandale. 2 Nearly twice the number given in my Catalogue of 1882, after elimination of the Madagascar species which are now placed in the genera Mantidactylus, Blgr. and Aglyptodactylus, Blgr. [4320 2 Records of the Indian Museum. [Vo1L. XX, The time has come to rid ourselves of the empirical methods which have necessarily prevailed so long in zootaxy, and to en- deavour to group species, as far as possible, according to their probable phylogenetic relationships, and for this purpose it is desir- able to fix one’s ideas by establishing a theoretical prototype from which phyletic lines may be drawn up. This I have re- cently attempted to do in a paper! of which an abstract is here given. The Fivmisternia are certainly derived from the Arcifera, as shown by their ontogeny, and among the latter the Cystignathidae agree in so many points with the Ranide that we may legiti- mately assume a direct genetic relationship between them. Dealing first with external characters, I consider the com- plete separation of the outer metatarsals by web as the most primi- tive character, which is not correlated with the degree of develop- ment of the web between the toes. In all the series of allied forms in which the phyletic tendencies are clearly indicated, we can follow the gradual reduction of the membrane; the species with fully webbed toes are, therefore, the least specialized, so far as this character is concerned. The dilatation of the tips of the digits is a specialization culminating in the large scansorial discs of the species adapted to an arboreal life. ; The primitive frog must have had a well-developed tympanum covered by a very thin skin. The reduction of the organ, which may be completely concealed under the thick skin, leads to its suppression (R. pleskez). The prominent glands on the back have often a tendency to run together in longitudinal ridges, irregular at first and ulti- mately localized, such as the dorso-lateral fold which characterizes a great number of species. However, this fold may again disap- pear, as some species of Hylorana seem to show; it is therefore necessary to distinguish, from the other characters taken in con- junction, whether the absence of the fold is primary or secondary. The skeleton affords important indications for judging of the phylogenetic relationships. I have limited myself to the use of characters which may be ascertained without difficulty on spirit specimens. Such are those derived from the skull, which can be examined by lifting up the skin, usually feebly adherent, and the pectoral arch, which can be exposed by making an incision along the breast and removing the muscles. ‘The shape of the terminal phalanges is easily revealed by the dissection of the tip of one of the fingers or toes. I regard as the most typical a skull such as that of R. hexa- dactyla, in which the nasals are large, and in contact with each other and with the frontoparietals, the upper surface of the eth- moid being covered over. From sucha type we may derive on the one hand those forms in which the cranial roof is expanded, and 1 Bull. Soc. Zool. France, 1918, p. 111. 1920. ] G. A. BOULENGER: Frogs of the Genus Rana. 3 the bones rugose and more or less confluent with the skin, on the other those in which the nasals and the frontoparietals are reduced. Most species agree with the type of the genus, Rana tem- porarta, in having a strong, horizontal clavicle {so-called precora- coid), and a simple omosternum (episternum). But the omo- sternum may be forked at the base, A-shaped, and this I regard as a specialization; whilst the oblique direction of the clavicle, diverging from the coracoid towards the median line, as in a few African species, is certainly ain approximation to the original condition in the Cystignathidae. The African frogs of the subgenera Hildebrandtia and Ptychadena show a high specialization in the reduction of the clavicles. The species with simply pointed terminal phalanges I regard as the most primitive ; a transverse distal expansion, which may be carried so far as to give the bone the shape of a T or a Y, in con- nexion with the scansorial discs, isa departure from the primitive type, and so is the claw-shaped phalanx which is characteristic of Ptvchadena.! Basing our considerations on these theoretical conceptions, we find that Rana hexadactyla is, among Asiatic species, the nearest approach to the ideal prototype: Outer metatarsals separated, fully webbed toes, pointed fingers and toes, distinct tympanum, absence of dorso-lateral glandular fold, condition of the skull. In the shoulder-girdle, with horizontal clavicles and forked omosternum, it is, however, more advanced than some of its African congeners. I therefore start with R. hexadactyla, from which the series headed by R. tigrina and R. grunniens can be directly derived. How other series, corresponding to the subgenera into which the genus is divided, may be derived from Rana, sensu stricto, is expressed in the synopsis given further on. Having explained the principles by which I have been guided in the classification of the species, I need hardly add that their application is not without many difficulties, which I am still unable to overcome. I trust, however, that the present arrangement con- stitutes a marked progress on past attempts. A few words of explanation are necessary concerning the method of taking measurements. The length of the head and of the snout are taken along the axis, and the posterior extremity of the head corresponds to the articulation of the skull with the vertebral column, which can be approximately ascertained, in the flesh, by feeling with the points of the compasses. The width of the head is the greatest width, at the commissures of the jaws. The tympanum,” of which the greatest diameter is given, is compared with the eye, measured along the side of the head. The limbs are measured fully stretched out, the hind limb from the 1 Cf. Boulenger, C.R. Ac. Sci. Paris, CLXV, 1917, p- 987: 2 In a recent paper published in the Records of the Indian Museum (XV, 1918, p. 97), Mr. Baini Prashad proposes to substitute the name ‘ tympanic area ’ 4 Records of the Indian Museum. [VoL. XX, middle line of the thigh where it joins the body. By foot is meant the foot without the tarsus; it is measured from the tarso-meta- tarsal articulation. Each finger or toe is measured from the point at which it joins its fellow, and if this is not the same on both sides, as in the case of the fourth toe, from the point most remote from the tip. The length of the first toe is reckoned from the distal extremity of the base of the inner metatarsal tubercle. Genus. Rana, L. Tongue extensively free and more or less deeply notched and bifid behind. Vomerine teeth (exceptionally absent). Pupil roundish-subtriangular or horizontal, or rhombic and very contrac- tile! Fingers free, toes more or less extensively webbed (excep- tionally nearly free). Omosternum and sternum with a bony style. No intercalary bone between the penultimate and distal phalanges. Divided into 9 subgenera :— I. Clavicles strong, straight or feebly curved, horizontal or directed forward, narrowly separated on the median line. A. Digits not dilated at the end, or with dilatations devoid of horizontal groove. 1. T'ympanum present ; squamosal not forming a suture with the maxillary. a. Outer metatarsals separated by web, at least in the distal half. Rana, sensu stricto. Type: R. temporaria, L. 14 Eurasian species, 22 American, 11 African, 45 Indo-Malayan, 1 Papuan. 6. Outer metatarsals united or separated only in their distal extremity ; omosternum usually forked at the base.? Tomopterna, D. et B. Type: T. delalandii, D. et B. 4 Indian species, 4 African. Burrowing forms, connected with Rana (XR. tigrina-limnocharis group) through the Indian R. rufescens, Jerd. 2. Tympanum present ; squamosal forming a suture with the maxillary. a. Outer metatarsals completely united ; omosternum entire. Pyxicephalus, Vsch. Monotype: P. adspersus, Tsch., Africa. Burrowing form like the preceding, probably derived from another group of Rana. 6. Outer metatarsals separated in the distal third or fourth; omosternum forked at the base. Aubria, Blgr. Monotype: R. subsigillata, A. Dum., Africa. Probably derived from the RX. tigrina group, like Tomopterna, but in a different direction. to ‘tympanum’ as universally used. When we say the tympanum is distinct, we do not convey the idea that it is exposed ; just as we are fully justified in stating that the eye of a frog is distinct even when the transparent lower lid is drawn over it. Mr. Baini Prashad has quoted various authors to show that ‘‘a great deal of confusion exists regarding the tympanum being a structure distinct from the skin or otherwise.’’ He should have referred to the introduction to my book, ‘The Tailless Batrachians of Europe’ (Ray Society, 1897), in which (p. 11), dealing with the external characters, I have thus described the state of things :— ‘“ The tympanum, or drum of the ear, is absent in Bombinator and Pelobates. When present it may be concealed under the skin, as in some specimens of Discoglossus, Pelodytes, and Bufo vulgaris, or appear on the temple behind the eye as a round or oval disk covered with thin skin.”’ 1 As in R. corrugata, kuhlii and spinosa. f 2 The character suffers exceptions, as Miss Procter has pointed out to me that the omosternum may be simple in specimens of R.delalandii. Is this to be regarded as a case of reversion to the original condition? It shows at any rate that great systematic importance cannot be attached to the shape of the omo- sternum, 1920.] G. A. BoULENGER: Frogs of the Genus Rana. 5 3. No tympanum ; outer metatarsals separated in the distal third or fourth ; omosternum entire. Nanorana, Gthr. Monotype: N. pleskez, Gthr., Kashmirand Thibet. Con- nected with the R. liebigii group through R. blanfordii, Blgr. B. Toes, often also fingers, dilated at the end, the dilatation, or disc, bearing a crescentic or horseshoe-shaped horizontal groove. 1. Outer metatarsals united or separated only in the distal third ; omosternum forked at the base. Discodeles, Blgr. Type: R. guppy, Blgr. 6 Indo-Malayan species, 3 Mela- nesian. Connected with Rana (RX. grunniens group); leads to the Indo- Malayan, Papuan, and Melanesian genera Cornufer, Tsch., and Platymantis, Gthr. 2. Outer metatarsals separated at least in the distal half ; omosternum entire. Hylorana, Tsch. Type: R. erythraea, Schleg. 58 South Asian species, 1 African, 5 Papuan and Melanesian. Completely connected with Rana (Ranae typicae) ; leads to the Indo- Malayan genera Stauwrois, Cope, and Simomantis, Blgr.! II. Clavicles very slender, curved or directed obliquely backwards, widely sepa- rated on the median line. A. Outer metatarsals united ; omosternum entire. Hildebrandtia, Nieden. Type: R&. ornata, Peters. 7 species from Africa. Burrowing forms. B. Outer metatarsals separated ; omosternum forked at the base; distal pha- langes claw-shaped. Ptychadena, Blgr. Type: R. mascareniensis, D.et B. 16 species from Africa, These two last subgenera are probably derived, as divergent series, from a common ancestral type connected with the subgenus Rana. The following diagram expresses the relations between these subgenera, as I conceive them. Ptychadena. Aubria. Hylorvana. Dtscodeles. Nanorana. a oie ee ae vs Rana. Hildebrandtia. Tomopterna, —————. ——_———-Pyxicephalus. Subgenus Rana, s. str. SYNOPSIS OF THE SPECIES. I. Dorso-lateral glandular fold absent or, if present, not connected with the supratemporal fold; outer metatarsals separated at least in the distal half. A. Tympanum very distinct, smooth; nasal bones in contact with each other, with two exceptions? ; omosternal style forked at the base. 1. Inner metatarsal tubercle small but very prominent, pointed, digitiform ; _ fingers pointed ; toes webbed to the tips ; male with external vocal sacs. Vomerine teeth in strong oblique series in the adult ; first finger longer than second; toes pointed; tibia 2 to 25 times as long as broad; throat and belly with granules and small warts... ue .. &. hexadactyla, Less. (Gate Boulenger, Ann.and Mag. N. H. (9) |, 1918, p. 372. 2 R. microdisca and palavanensis. . ; 6 Records of the Indian Museum. [Vor. XX, Vomerine teeth in small groups; first and second fingers equal; tips of toes swollen or dilated into very small discs ; tibia 23 to 34 times as ee as broad ; throat and belly usually smooth ... &. cyanophlyctis, Schn. 2. Inner metatarsal tubercle small or ‘large, blunt or compressed, not digiti- form ; toes 4 to entirely webbed. a. Toes with obtuse or slightly swollen tips ; vomerine teeth between the choanae, often extending posteriorly beyond them ; male with a more or less developed pad on the inner finger. a. No outer metatarsal tubercle; toes # to entirely webbed ; first finger longer than second ; tibia 2} to 3 times as long as broad; male with external vocal sacs. Toes completely webbed; tibio-tarsal articulation reaching tip of snout .. &. verruculosa, Roux. Toes completely or nearly completely webbed ; tibio- tarsal articulation not reaching tip of snout .. R.tigrina, Daud. Toes incompletely webbed, or with the web deeply notched ; tibio-tarsal articulation not reaching tip of snout .. &. cancrivora, Gravh. B. Usually z a more or less distinct outer metatarsal tubercle. * Toes 2 to 3 webbed; tibia 3} to 4 times as long as broad ; head and back rough with warts of unequal size; male with internal vocal sacs eeu pais verrucosa, Gthr. ** Toes usually not more than 3 webbed, rarely 2; male with ex- ternal vocal sacs. Toes } to 2 webbed; tibia 2% to 35 times as long as broad ; tibio-tarsal articulation not reaching beyond tip of snout ; first finger longer than second ... &. limnocharis, Wiegm. Toes not quite } webbed ; tibia 3 to 4 times as long as broad ; tibio- tarsal articulation not reaching tip of snout ; first finger not or but very slightly longer than second fe on .. R. greentt, Blgr. Toes barely 4 webbed ; tibia 4 to 4% times as long as broad ; tibio-tarsal articulation reaching tip of snout or bey ond ; first finger longer than second ... R. brevipalmata, Peters. j. Toes with the tips dilated into distinct discs; male without or with inter- nal vocal sacs, without enlargement of the fore limb or inner finger, often with tooth-like bony processes in front of lower jaw. a. Vomerine teeth extending behind level of choanae, or entirely behind them. * Tibia 3 to 4 times as long as broad ; nasal bones large and in contact with each other and with the frontoparietals. + Toes $ to entirely webbed ; interorbital region flat. § Fi irst finger much longer than second. Tympanum 5 to % diameter of eye; tibia more than twice in length ‘from snout to vent; heels not over- lapping ; male without vocal sacs, without tooth-like processes in lower jaw . R. grunniens, Daud. Tympanum % to § diameter of eye ; tibia re to 24 times in length ‘trom snout to vent; heels overlapping ; discs of toes very small, oie without vocal sacs, with tooth-like Bee esees in lower jaw... . &. macrodon, D. et B. Tympanum j to 2 diameter of eye; tibia 2 to 23 times in length fom snout to vent; heels not overlapping ; discs of toes rather large ; male with vocal sacs, with tooth-like gy lees in lower jaw wan ... R. magna, Stejn. Tympanum ¢ to } diameter of eye ; tibia nearly 2 to 23 times in length from snout to vent ; heels ov erlapping ; discs of toes very small; male with vocal sacs, with tooth-like processes in lower jaw ... R. modesta, Blgr. §§ First finger not much longer than second. Tympanum 4 size of eye; first finger as long as ora [v. Kamp. little shorter than second _,,, a ... &. microtympanum, 1920. ] G. A. BOULENGER: Frogs of the Genus Rana. 7 Tympanum 3 to 3 diameter of eye ; first finger a little longer than second; tibia 13 to 2+ times in length from snout to vent ; heels overlapping ; male without vocal sacs, without tooth-like processes in lower jaw R. dortae, Blgr. ++ Toes 2 to nearly entirely webbed ; male with the interorbital region very convex, swollen behind, with tooth-like processes 1n the lower jaw, no vocal sacs, and the tympanum as large as or a little larger than the eye. Tibia at least twice in length from snout to vent ; inner metatarsal tubercle } to 2 length of inner toe; inter- orbital swelling of male rounded behind ... R.macrognathus, Blgr. Tibia at least twice in length from snout to vent ; inner metatarsal tubercle 4 to 4 length of inner toe ; inter- orbital swelling of male followed by a dermal flap... XR. pileata, Blgr. Tibia 1+ to 2 times in length from snout to vent ; inner metatarsal tubercle about 3 length of inner toe ; back with 8 or 10 glandular longitudinal folds ; interorbital swelling of male foliowed by a knob-like prominence R. plicatella, Stol. +tt Toes 4 to } webbed ; tibia 1% to 2 times in length from snout to vent. : Tympanum 4 to 2 diameter of eye ; inner metatarsal tubercle feebly prominent, 2 to 2 length of inner toe ; male without vocal sacs, without tooth-like promi- nences in lower jaw Hy ah ... R. hascheana, Stol. Tympanum 2 to # diameter of eye; inner metatarsal tubercle very prominent, 2 to 3 length of inner toe; male with vocal sacs and tooth-like prominences in lower jaw = -