122 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXVII » 



In regard to the development of the neural spines, I agree with the 

 statement of Dr. NichoUs (p. 606) and I find that the neural spine of the 

 seventh vertebra is as upright as that of the eighth. The cartilaginous 

 ribs of the third vertebra of R. tigrina are said to be very like those of 

 P. fuscus and this condition is obviously common to more than one Indian 

 frog. The third vertebra of some of tne examples of Jiexadactyla also show 

 this character and the third vertebra of these two Indian species are to be 

 distinguished by a flange or an osseous tubercle in tigrina alone. This 

 tubercle or flange may perhaps represent the partial bifurcation of the 

 diapophyses described by Dr. Bourne (q) as an abnormal occurrence in 

 temporaria. As regards the diapophyses of the eighth vertebra, it may be 

 mentioned that its stouter nature is rather an exception than a rule, and 

 in the specimens that I have sent to the Indian Museum they will be seen 

 to be not bigger than the transverse process of the seventli vertebra. The 

 sacral diapophysis is certainly cylindrical in tigrina. I entirely agree with 

 the description of the coccyx in Dr. Nicholls's paper, but in respect of the 

 shoulder girdle, although there is a slight overlap, the ventral suture of 

 the two corocoids which meet in a median bar in front, passes through 

 the median axis of the girdle. Dr. Nicholls's text fig. 3A showing the 

 right corocoid beyond the mid-ventral line, is rather an exaggeration. The 

 overlapping condition is certainly a primitive feature which tigrina has 

 retained, and in the metamorphosing larvss of this, as in other Kanid larvse 

 (r) it is the epicorocoidal cartilages that overlap and the left corocoid bone 

 extends slightly dorsaily over the right, while ventrally they meet in a 

 median suture. 



(b). The skull: — Dr. Boulenger appends a short description of the skull 

 of B. tigrina to his definition of the species (s) and in certain regards it 

 needs amplification. The cartilaginous basis of the skull is really confined 

 to the processes given off from the nasal capsule which is, however, perfectly 

 ossified ; the principal processes being the transverse ones meeting the 

 cartilaginous epiphyses of the pterygoid, the anterior and the anterolateral 

 and the alar cartilages. The floor, the roof and the septum of the olfactory 

 capsule are ossified by the great development of the othmoid bone — the 

 cornets are present in the form of powerful turbinated bones. The large 

 nasals which overlie the bony capsule, — occasionally with bony outwardly a 

 verj"- short directed spines, — are united with one another and with the fronto- 

 parietals so completely that the sutures may be lost or may be faintly indi- 

 cated by grooves. The osseous floor of the nasal capsule is underlaid by 

 two equally large vomers the outer borders of which have two processes 

 enclosing a deep notch between them, — the anterior process almost meeting 

 the maxillary bone, while teeth are borne on the postero-lateral border. 

 The sagittal and coronal sutures are only indistinctly marked or not at all, 

 and the upper surface of the skull is either flat or slightly convex (noticed 

 in R. temporaria and R. oxyrUnus (t). The parietal ridge is generally 

 strongly marked, extending backwards to the apex of the heart-shaped 

 foramen magnum. The mastoid ridges and the mastoid elevations are pro- 

 minent. The lateral cartilaginous portions of the cranium are completely 

 replaced by the backward extension of the spenethmoid which is incorpo- 

 rated behind into the ala magna. Thus the foramen pro ramo-nasalis, 

 foramen opticus and foramen oculomotorius are simple perforations in the 

 sphenethmoidal bone. In some specimens the downward prolongation of 



iq) 1894, Bateson, Mat., Stud. Var., p. 124, and 1884, Bourne, Q. J. M. Sci., 



XXIV, p. 86. 

 (r) 1901, Gadow., Camb. Nat. Hist., Amph. Kept., p. 25. 

 (s) 1918, Bee. Ind. Mus., Vol. XV., p. 57. 

 it) 1889, Ecker, Anat., Frog. p. 23. 



