GENERAL CONSIDERATIONS. 



The Territory of Alaska beiug separated from the rest of the contineut of America by no 

 barriers which are impassible to mammals, we shall not expect to discover a distinct mammalian 

 fauna within its borders. Lying partly within and partly without the Arctic Circle, and being 

 bisected by the isothermal of 32° F., we shall look iu its southern portions for representatives 

 of the north-temperate fauna, and in its northern portions for representatives of the Arctic or 

 circumpolar fauna. The facts bear out these a iniori conclusions. We find no single species of 

 mammal within the boundaries of Alaska which is not to be found also without those boundaries. 

 Some enter the Territory from the east, or perhaps from across Bering Straits ; others from the 

 south. They are the familiar species of the United States, British America, or Siberia and the 

 circumpolar zone generally. 



The interest attaching to the mammals of Alaska arises, therefore, not from their novelty, 

 but rather from the fact that they are the northernmost representatives of their species. It is in 

 Alaska, as iu Arctic British America, that we find the northern boundaries of the range of a 

 number of American mammals. We find species characteristic of a temperate region contending 

 with the rigors of an Arctic climate, few in numbers, and, as Mr. Allen has pointed out, small in 

 size. Ou the other haul, we find species rarely or never met with as far south as the United 

 States, having their center of distribution within the Arctic Circle, abundant and of large size. 



In 1870 Mr. Dall published a list of the mammals of Alaska, including the aquatic species. 

 This list comprises 70 species and subspecies of recent mammals, of which 25 belong to the orders 

 Pinnipedia and Cetacea. Six of the species, however, are now generally regarded identical with 

 seven others in the list, and two additional species {Sorex Eossii and S. pachypus) appear never to 

 have been described. The number of valid species and subspecies is, therefore, reduced to 62. 

 The list is as follows: * 



Sorex Forsteri. 



Sorex Gooperi. 



Sorex pachypus (undescribed). 



Sorex Bossii (undescribed). 



Lynx canadensis. 



Vulpes fulvus. 



Cnnis occidentalis [= Canis lupus griseo- 



albus.] 

 Tulpes fulvus decussatus. 

 Vulpes fulvus argenfatus. 

 Vulpes lagopus. 

 Mustela Pennanti. 

 Mustela americana. 



> {=P.ermi)iea]. 



Putorius vison. 



Putorius pusillus [=P. vulgaris]. 



Putorimnoveboracensis 



Putorius Bichardsoni 



Gulo Ihscus. 



Lutra canadensis. 



Enhydra marina. 



ProcyoH lotor. 



JJrsus horribiUs. 



JJrsus Bichardsoni. 



Ursus americanus. 



Ursus maritimus. 



"Tho fossil species given by Mr. Dall are purposely omitted bere ; also the Eskimo Dog, ■which may or may not be 

 indigenous. 



231 



