yo AMERICAN FISHERIES SOCIETY. 



monids, Cyprinodontids, Anguillids, Gasterosteids, Atherinids, 

 Labracids, Scieenids, Embiotocids, Cottids and Gadids, and 

 among these we find the families which are represented by the 

 same genera in both the old and new worlds. 



The fresh-water species and even the genera of most of these 

 families are, however, to a large extent, peculiar to the interior 

 waters ; of the others, (i) some are anadromous, like certain of 

 the Salmonids, Clupeids and Labracids ; (2) others inhabit fresh 

 and salt water almost indifferently, as the Dorosomids, many 

 Cyprinodontids, and most Gasterosteids, and (3) one (the eel) per- 

 haps should be considered as a salt-water rather than a fresh- 

 water species, inasmuch as it is catadromous and appears to 

 breed only in the sea. Conversely, these fishes which resort to 

 fresh water to spawn and therein spend their early days may be 

 considered to be fresh-water forms. If all species which, to 

 some extent, run up into fresh water were included, the list 

 might be very greatly increased, and it is by this inclusion of 

 these species running up into fresh water that the faunas of 

 other countries have been unduly enhanced. 



If now we consider the bearings of the known facts, we may 

 deduce the following conclusions': 



(i) The number of family types peculiar, or almost peculiar, 

 to North America and the very large number of genera also 

 confined to the temperate and cold regions of the continent, indi- 

 cate that the region specified has such characteristics as to en 

 title it to be considered a primary geographical division of the 

 globe, which will appropriately bear the name of the Anglo- 

 gaean realm, inasmuch as its habitable portions are occupied by 

 the largest portion of the Anglo-Saxon race. Several of the 

 families peculiar to this realm are almost coincident in their 

 range with its limits, and such coincidence is especially mani- 

 fested in the case of the family of Centrarchids. 



(2) If we compare the constituency of our ichthyic fauna with 

 that of the Eurasiatic realm, we find several notable contrasts. 

 The North American is distinguished by the great development 

 of Acanthopterygian types, while there are few in the Eurasi- 

 atic one. North America has as many as 180 species, while nine- 

 teen are all that have been credited to Eurasia. The Centrar- 



