Dr. A. Giinther on the Geographical Distribution of Reptiles. 311 



The supraoesophageal ganglion is a triangular mass with its apex 

 behind : the two front corners terminate in large nerves. 



The nervous system of C. Persicce differs but little from that of 

 C, hesperidum, and offers the same extraordinary amount of 

 variation. The two species, however, could be at once distinguished 

 by the superior size of the suboesophageal ganglion in C. Persicce, in 

 which species also the last pair of nerves (fig. 10) is given off more 

 posteriorly, while both they and the central stem are considerably 

 swollen at their origin, so as to give the hind margin of the ganghon 

 a three-pronged outline. 



ZOOLOGICAL SOCIETY. 



July 27. 1858.— Dr. Gray, F.R.S., V.P., in the Chair. 



On the Geographical Distrtbution of Reptiles. 

 By Dr. Albert Gunther. 



[Concluded from p. 237-] 



Part II. 



On the Geographical Distribution of Batrachians. 



In the accounts given of the geographical distribution of animals, 

 we find only a few general statements in which divisions of the earth's 

 surface are characterized for their Batrachio-fauna. The presence of 

 tailed Batrachians in the northern parts of the globe, the scarcity of 

 Batrachians in Africa, gigantic forms between the tropics, and the 

 abundance of Tree-frogs in South America, form the general results of 

 those attempts. The faunas of some provinces were most accurately 

 composed ; but I am not aware that the like has been attempted with 

 respect to all the single parts of this suborder. The Batrachians 

 are better adapted than Snakes to range over large spaces ; and this 

 is especially the case with some Batrachians of the northern tem- 

 perate part of the globe. Raiia esculenta, Bufo vulgaris, and Hyla 

 arborea are spread over the whole space of Europe and Asia, be- 

 longing to the Palsearctic region ; Cantor found them again south 

 of Japan, on the Chinese island of Chusan. Rana temporaria 

 reaches beyond even these parts, being equally spread over the tem- 

 perate regions of the New World. But none of the species are to be 

 called cosmopolitan ; and the differences between the different crea- 

 tions are such, that we have not even a true cosmopolitan genus. 

 In looking for genera with the widest range, we may mention Rana, 

 Bufo, and Hyla — genera which exhibit also the widest-spread species. 



Bufo is wanting only in Australia ; the most numerous and largest 

 of its species are met with in Tropical America. Rana is entirely 

 wanting in Australia, and represented in the most northern parts of 

 Tropical America by a single species only ; the East Indies and Africa 

 produce most of the species, some from the former region being di- 

 stinguished by their gigantic size, but rivalled by R. mugiens from 

 N. America, — some from the latter region being peculiar on account 

 of their long and slender toes. Hijla is entirely wanting in the ^Ethio- 



