318 ZOOLOGICAL GEOGRAPHY. [pArt hi. 



this class are toads of the family Engystomidse ; tree-frogs of 

 the family Polypedatidse ; and several genera of true frogs, 

 Eanidee. 



Fresh-ivater Fishes. — The more remarkable and characteristic 

 fishes inhabiting the fresh waters of the Oriental region belong 

 to the following families : Nandidre, Labyrinthici, Ophiocephalidce, 

 Siluridse, and Cyprinidce ; the last being s})ecially abundant. 



The sketch here very briefly given, must be supplemented by 

 an examination of the tables of distribution of the genera of all 

 the Mammalia and Birds inhabiting the region. We will now 

 briefly summarize the results. 



Summary of the Oriental Vertehrata. — The Oriental region 

 possesses examples of 163 families of Vertebrata of which 12 

 are peculiar, a proportion of a little more than one-fourteenth 

 of the whole. 



Out of 118 genera of Mammalia 54 seem to be peculiar to 

 the region, equal to a proportion of o% or a little less than half. 

 Of Land-Birds there are 342 genera of which 165 are peculiar, 

 bringing the proportion very close to a half. 



In the Ethiopian region the proportion of peculiar forms 

 both of Mammalia and Birds is greater ; a fact which is not 

 surprising when we consider the long continued isolation of the 

 latter region — an isolation which is even now very complete, 

 owing to the vast extent of deserts intervening between it and 

 the Palaearctic region ; while the Oriental and Palcearctic were, 

 during much of the Tertiary epoch, hardly separable. 



Insects. 



Lcpidoptcra. — We can only glance hastily at the more pro- 

 minent features of the wonderfidly rich and varied butterfly- 

 fauna of the Oriental region. In the first family DanaidiE, the 

 genera Danais and Eujjlaa are everywhere abundant, and the 

 latter especially forms a conspicuous feature in the entomo- 

 logical aspect of the country; the large "spectre-butterflies" 

 {Hcstia) are equally characteristic of the Malayan sub-region. 

 Satyridee, though abundant are not very remarkable, DeUs, 

 Melanitis, Mycalesis, and Ypthima being the most characteristic 



