288 



is more nearly related to the australian Cystignathidae than 

 to the Pelobatidae. 



The Ranidae are distributed in the entire Archipelago, though 

 generally decreasing in number of species eastward. So they 

 are less numerous in New Guinea than in the much smaller 

 island Celebes, and in this island, again, their number of 

 species is smaller than in Java. It is, however, remarkable that 

 a comparatively large number of endemic species and even 

 two endemic genera inhabit the Bismarck and Solomon islands 

 in the extreme eastern part of the area of distribution of 

 this family. 



A similar phenomenon is shown by the Brevi^ipitidae in 

 still higher degree. This indian family has its largest number 

 of genera and species in New Guinea, and the small Sudest 

 island, east of New Guinea, possesses even an endemic sub- 

 family, the Genyoplivyninae. 



The distribution of the Amphibia does not show a sharp 

 boundary between the Indian and the Australian regions. 

 Whereas the western part of the Indo-Australian Archipelago, 

 including Celebes and the Lesser Sunda islands, has a purely 

 indian character concerning its fauna of Amphibians, the eastern 

 part, including the Moluccos and the Timor archipelago, is 

 a region of transition, in which the indian and the australian 

 fauna are mixed. Moreover, this region shows an own character 

 by the high development of the Brevicipitidac among the 

 indian, and the Hylidae among the australian families. 



The characteristics of the distribution of the Amphibia in 

 the Archipelago may be explained in the most simple manner 

 by assuming the former existence of narrow and inconstant 

 land connections (Sarasin) between the Sunda islands and New 

 Guinea, as has been explained by me '). Such narrow bridges 

 must be an obstacle for the distribution of Amphibians, which 

 generally are rare on small islands. This fact may be shown 

 by comparing the numbers of species of Amphibia inhabiting 

 various islands of the Indo-Australian Archipelago with those 

 of the Lacertilia of the same islands -), f. i. : 



1) Nova Guinea, IX, i, 1909, p. 47. 



2) Taken from: N. de Rooy, The Reptiles of the Indo-Australian Archipelago, 

 I, Leiden, 191 5. 



