314 Zoological Society : — 



a complete series of East Indian Batrachians, as considerably to 

 increase the number of the species formerly known ; neverthe- 

 less the fact appears to be, that this region is excessively productive 

 of individuals (especially of certain species, as in Snakes), but that it 

 is not in the same way rich in generic, and still less in specific forms. 

 There is some resemblance in this respect to the Palsearctic region. 

 We may state 60 as the number of species, which gives a single 

 species to every 66,000 square miles. 



All the Batrachians belong to the Opisthoglossa, not the half of 

 which are Platydactyla. The true Hyla are wanting, and, as in 

 Africa, replaced by genera without dilated processes of the sacral ver- 

 tebra. Ceylon is comparatively rich in species ; but as, in general, 

 the Batrachians are adapted for spreading over a much greater 

 space than other reptiles, we do not find so peculiar a fauna of 

 them in this island. The following species are known to be found in 

 Ceylon : — 



Rana kuhlii. *Ixalus variabilis. 



vittigera. * leucorhinus. 



tigrina. * poecilopleurus. 



hexadactyla. aurifasciatus . 



malabarica. Polyped. microtympanum. 



Bufo melanostictus. maculatus. 



* kelaartii. * eques. 



Kaloula pulchra. 



Only those species marked with an asterisk are peculiar, the others 

 exhibiting not even remarkable varieties. 



IV. Australian Region. 



Characteristic forms. — Myobatrachus^ Limnodynastes^ Chiroleptes, 

 Heleioporus, Uperoleia, Pseudophryne, Chelydobatrachus, Litoria, 

 Pelodryas. 



Forms common to other regions. — Cystignathus, Hylarana, 

 Cornufer, Platymantis. 



Of thirty species which are known to belong to this region, we 

 have on the average a single species to each 100,000 square miles, 

 and therefore only to each 33,000 square miles of the known part of 

 Australia and its islands. Just the half of the species are Opistho- 

 glossa platydactyla. 



Australia produces one Batrachian without a tongue ; and if there 

 were known such a Batrachian from the Indian region, all the 

 Aglossa would be equally distributed through the Tropical world, each 

 part producing a peculiar type, — viz., Africa the genus Bactylethra, 

 South iVmerica the genus Pipa, Australia that of Myobatrachus. 

 Secondly, this region is distinguished by the total absence of true 

 Ranidce and BufonidcB. iVmong other characteristic forms, Pelodryas 

 especially deserves to be mentioned, representing the genus Phyl- 

 lomedusa of the New World, but distinguished by a web between 

 the toes. Hylarana extends, in one variety of H. erythrcea, to the 

 islands of the Pacific (S. Christoval) ; but the geographical distribu- 



