SOME ASPECTS OF THE ANATOMY OF ANURA (AMPHIBIA)-A REVIEW* BY L. S. RAMASWAMI (From the Department of Zoology, University of Mysore, Central College, Bangalore) Received July 15, 1939 (Communicated by Prof. A. Subba Rau, D.so., F.R.M.s.) CONTENTS PAGE I. Introduction .. .. .. .. 42 II. Literature Selected .. .. .. .. .. 45 III. Review :- (a) Narial Region .. •. .. .. .. 45 (b) Prechoanal Sac .. •. .. .. .. 47 (c) Septomaxilla .. .. .. .. .. 48 (d) Eminentia Olfactoria .. .. .. .. 49 (e) Sphenethmoid .. .. .. .. .. 50 (f) Subethmoidal Cartilage .. .. .. .. 50 (g) Maxillae .. .. .. .. .. 51 (h) Prevomer .. .. .. .. .. 52 (i) Palatine Bone .. .. .. .. .. 56 (j) The Nasal, Frontoparietal, Squamosal, Pterygoid, Quadratojugal and Parasphenoid Bones .. .. 58 IV. The Middle Far Region .. .. .. .. 60 V. The Pterygoquadrate and its Attachments, and the Arteria Carotis Interna .. .. .. .. .. 63 VI. Bursa Angularis Oris (Fuchs) or the Mundwinkeldruse .. 65 VII. The Lower Jaw .. .. .. .. .. 66 VIII. The Hyolaryngeal Apparatus of Microhylidee and Pelobatidae 66 IX. The Vertebral Column .. .. •. .. .. 68 X. Summary and Conclusions .. .. .. .. 71 XI. Acknowledgement .. .. .. .. .. 76 XII. Bibliography .. .. .. .. .. 77 XIII. Errata List .. .. .. .. .. 80 * Based on the published papers of the author and accepted for the Doctor of Science Degree of the University of Madras, March 1938. 41 B3 F 42 L. S. Ramaswami I. Introduction AT the outset, it must be pointed out that under the title of anatomical studies of Indian and some extrapeninsular Anura, I have examined the cranium and larynx by the method of sections and also by gross study, and the morphological features of the vertebral column of some Indian anuran species by the latter method. It may be remarked here, that the study of cranial morphology by the method of sections revived at the incentive, given by Dr. de Villiers of South Africa, is still young. The various internal anatomical characters exhibited by the anuran species have to be examined comparatively and then only we can embark upon any generalizations. As we go on working, the only procedure can he, therefore, to correlate and compare such features as become manifest in the several families and sub- families and then try to assess their usefulness from the view-point of taxo- nomy. In trying to correlate these characters, we have to bear in mind that the environmental conditions may have a profound influence upon the organization of individuals, and that secondary modifications in response to changed surroundings are often largely developed. I have examined the cranial morphology of adult specimens of the following species and in many cases more than one specimen has been utilised for this purpose (author, 1932, 1932 a, 1934, 1935, 1935 a, 1937) 1. Microhylidce. Microhyla ornata Dam. & Bibr. Kaloula pulchra Giinth. part (K. pulchra taprobanica Parker, 1934) Uperodon systoma Schneid (Cacopus systoma Schneid). Glyphoglossus molossus Gunth. 2. Ranid^e. Rana hexadactyla Less. Rana cyanophlyctis Schneid. Rana curtipes Jerdon. 3. Rhacobhoridce ( Polypedatidae). Rhacophorus maculatus Blgr. Rhacophorus microtympanum Gunth. Philautus petersi Blgr. Philautus chalazodes Giinth. Philautus oxyrhynchus Giinth. Some Aspects of the Anatomy of Anuva (Amphibia)—A Review 43 4. Bufonidrv. Bufo melanostictus Schneid. Bufo parietalis Blgr. Bufo hololius Gtinth. Bufo beddomli Gunth. Nectophryne misera Mocq. 5. Pelobatidce. Megophrys major Blgr. (M. gigas Jerd. = major Blgr.). Scaphiopus holobrookii Harlan. The descriptions of the sections of the larynx of Uperodon systoma Schneid, Kaloula pulchra Giinth. part (K. pulchra taprobanica Parker) and Microhyla ornata Dum. and Bibr. (author, 1932 b) are given; and morphological accounts of the larynx of Megophrys major Blgr. and Scaphiopus hammondii (author, 1935 b) and of the hyoid of these and of the South Indian Microhylid forms named above are dscribed. The morphology of the adult vertebral column in the following species is described (author, 1933) : 1. Rhacophoridce (Polypedatidae). Rhacophorus maculatus Blgr. Rh. eques Giinth. Rh. microtympanum Gunth. Philautus chalazodes Giinth. Ph. sylvaticus Rao. t Ph, nasutus Giinth. Ph. oxyrhynchus Giinth. Ph. sp. (marked B in the Central College Museum collection). 2. Ranidw. Micrixalus saxicola Jerd. Micrixalus sp. (marked A in the Museum collection). Nyctibatrachus major Blgr. N. pygmaus Blgr. N. sanctipalustris Rao (1920). Nannobatrachus kempholeyensis Rao (1937). Rana beddomii Gunth. R. bhagmandalensis Rao (1922). t This form has been since discovered to be a new species of 1ti yctibatrachus by Rao (1937), and is therefore, treated as Nyctibatrachus sylcaticus Rao. B3 a F 44 L. S. Ramaswami R. breviceps Schneid. R. brevipalmata Peters. R. crassa Jerd. ( = R. tigrina var. crassa Jerd.) R. cyanophlyctis Schneid. R. curtipes Jerd. R. diplosticta Blgr. R. gracilis Gravh. R. intermedius Rao (1937). R. leithii Blgr. R. leptodactyla Giinth. R. limnocharis Wiegm. R. malabarica Tsch. R. pantherina (R. tigrina var. pantherina Fitz.). R. parambiculamana Rao (1937). R. semipalmata Blgr. R. tenuilingua Rao (1937). R. sauyicees Rao (1937). The occurrence of a Bursa angularis oris or Mundwinkeldriise is reported by me (1933 a) in Glyphoglossus molossus Gunth., Uperodon systoma Schneid, Microhyla ornata Dum. and Bibr. Kaloula pulchra Gunth (K. pulchra taprobanica Parker) and in Rhacophorus maculatus Blgr. The Apodan genera Ichthyophis and Uraotyphlus were also investigated in this connection. With regard to the Microhylid species investigated by me, the genus Kaloula Gray has been subsequently split into two, Kaloula Gray and Rama- nella Rao by Parker (1934) and this splitting is based on the difference in the nature of the prevomer. Rao (1925) described a new genus of Micro- hylid frog from South India which he called Ramanella symbiotica and he makes no reference to the exact nature of the prevomer in this species. This form, however, was later discovered to be none other than a species of Kaloula, K. variegata Stoliczk. But Parker (1934) retains the generic name Ramanella for accommodating five species which were originally included under Kaloula Gray and according to him the difference between Kaloula Gray and Ramanella Rao is that in the latter, the prevomer is reduced and broken up. My descriptions of K. pulchra were drawn up from a specimen of the race which Parker subsequently described as K. pulchra tapyobanica (1934). As regards the other genera, I included Rhacophorus (Polypedates) under the family Ranidae following the observations of Gadow (1901) and Some Asj5ects of the Anatomy of Anura (Amphibia)—A Review 45 Boulenger (1882 and 1890). But Noble (1927 and 1931) has dissociated Rhacophorus from the Ranidae and erected a new family Polypedatid e, in which he includes Rhacophorus (Polypedates), Philautus and some other genera. Moreover, the genus Rana itself has been split into nine subgenera by Boulenger (1920), viz., Rana, Tomopterna, Hildebrandtia, Ptychadena, Aubria, Hylorana, Discodeles, Nanorana and Pyxicebhalus. The two species R. hexadactyla and R. cyanophlyctis come under the subgenus Rana s. str., while R. curtiies is included under the subgenus Hylarana. This splitting is very well supported by my anatomical observaions. In describing the Bufonid head (author, 1937), I have remarked in the introduction that Notaden is a member of the family Bufonid. I have followed Gadow (1901) and Noble (1931) in this, and Noble (1931) correctly points out that neither Notaden nor Myobatrachus shows any " affinity to bufonids found to-day outside Australia " and insists that they do not belong to the subfamily Bufoninae which according to Parker (in litt.) is approxi- mately equal to Bufonidx of Gadow and Boulenger. With regard to the other genus Nectes, it was placed as a synonym of Pseudobufo by van Kampen (1923) and this nomenclature is followed by Smith (1930). Further the Bufonid genus Cophophryne of Boulenger is treated by Noble (1931) under the family Pelobatidae. In connection with the vertebral column, I have examined members belonging to the two families Ranidoe and Rhacophorid e (Polypedatidee). Subsequent to the publication of a note on the proceelous nature of the 8th and 9th vertebrae in Rhacophorus maximus by Mookerjee (1932), it occurred to me that " if it could be shown that the vertebrae are uniformly proccelous in this genus Rhacophorus, then its iuclusion under the family Ranid e, becomes a questionable procedure ". I have examined four species of Rhacophorus of which one (R. maculates) confirms the observations of Nicholls (1915-16) in being diplasiocoelous. II. Literature Selected In referring to previous work I have largely restricted myself to recent workers who have studied the skull of anuran species by the method of sections. This does not necessarily mean that I have ignored the morpho- logical descriptions of other authors, and in some cases I have not been able to secure the necessary literature, and therefore, my bibliographical list may not be exhaustive. III. Review (a) Narial region.—The very first structure that we meet with in the rostral end of the anuran examples studied is the prenasal cartilage 46 L. S. Ramaswami associated with the premaxilla. In the Microhylid examples studied, it is noticed that Uperodon and Glyphoglossus possess both the prenasal cartilages (prenasalis superior and inferior) while their congeners Microhyla ornata and Kaloula pulchra (K. P. taprobanica) possess only the superior cartilage. On p. 2