A . The Europo-Asiatic (PaljEarctic) Eegion. — Its western 

 and sonthem boundaries coincide with those of the Northern 

 Zone, so that only those which divide it from North America 

 have to be indicated. Behring's Strait and the Kamtschatka 

 Sea have been conventionally taken as the boundary, but 

 this is shown to be artificial by the fact that the animals of 

 both coasts, as far as they are known at present, are not suf- 

 ficiently distinct to be referred to two distinct regions. As 

 to the freshwater fishes those of North-western America and 

 of Kamtschatka are but imperfectly known, but there can 

 be little doubt that the same agreement exists between them 

 as is the case with other classes of animals. The Japanese 

 islands exhibit a decided Palsearctic fish-fauna, which includes 

 Barbus and Cobitioids, forms strange to the North American 

 fauna. A slight influx of tropical forms is perceived in the 



