318 
ZOOLOGICAL GEOGRAPHY. 
[part III. 
this class are toads of the family Engystomidse ; tree-frogs of 
the family Polypedatidse ; and several genera of true frogs, 
Eanidse. 
Fresh-water Fishes . — The more remarkable and characteristic 
fishes inhabiting the fresh waters of the Oriental region belong 
to the following families : Nandidre, Labyrintliici, Ophiocephalidae, 
Siluridae, and Cyprinidae ; the last being specially 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 Vertebrata. — 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 fa 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 forma 
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 Pakearctic region ; while the Oriental and Pakearctic were, 
during much of the Tertiary epoch, hardly separable. 
Insects. 
Lepidoptera. — We can only glance hastily at the more pro- 
minent features of the wonderfully rich and varied butterfly- 
fauna of the Oriental region. In the first family Danaida?., the 
genera Danais and Euplcea are everywhere abundant, and the 
latter especially forms a conspicuous feature in the entomo- 
logical aspect of the country; the large “spectre-butterflies” 
( Hestia ) are equally characteristic of the Malayan sub-region. 
Satyridas, though abundant are not very remarkable, Debts, 
Melanitis, Mycalesis , and Ypfhima being the most characteristic 
