16 BIOLOGICAL SOCIETY OF WASHINGTON. 



thcr, has considered the several countries as constituents of a single 

 " region," called the Antarctic region, whose subdivisions were 

 designated as the Tasmanian, New Zealand, and Patagonian "sub- 

 regions," and which were, in his opinion, "almost identical." 

 On the whole I am now inclined to follow Mr. Allen in differentiat- 

 ing this realm from the South American, somewhat contrary to my 

 former views, although I do so with some hesitation. 



THE ANTARCTIC OR SOUTH CIRCUMPOLAR REALM. 



Mr. Allen has enunciated the following views respecting an Ant- 

 arctic Realm : 



" The Antarctic Realm is geographically almost wholly oceanic, 

 and its fauna hence consists almost exclusively of marine or pelagic 

 species. It necessarily embraces not only the Antarctic Zone, but 

 a large part of the cold south-temperate, since very few of its char- 

 acteristic species are wholly restricted to the Antarctic waters. It 

 will hence include not only the few small groups of Antarctic 

 Islands, but also Tierra del Fuego and the Falkland Islands, and 

 perhaps also the extreme southern shores of South America, while 

 some of its characteristic forms also extend to New Zealand, and 

 even Australia and the Cape of Good Hope. The only mammals 

 that can be considered as strictly characteristic of this region are 

 Pinnipeds and Cetaceans, of which several genera of each are almost 

 wholly restricted to it. A " South Frigid," "'Antarctic," or 

 "South Circumpolar" "Zone," "Region," or "Realm," has 

 been recognized by various writers for the marine invertebrates, 

 and, by von Pelzeln for birds, with limitations much as here as- 

 signed. While the number of species peculiar to it is small, it is 

 large relatively to the whole number represented, especially in the 

 colder latitudes. There is, of course, a broad belt along its north- 

 ern border of a transitional character, where Antarctic types over- 

 lap the range of groups characteristic of south-temperate lati- 

 tudes."-^^ 



As it is admitted that no terrestrial or fresh-water animals have 

 been found in the Antarctic regions, it is not obvious why such 

 a realm should have been proposed in connection with the distri- 



*Allen op. cit., p. 372. 



