INTEODUOTION. 27 



trum, Vaecinium, Bryanthus, Pyrola, Arctostaphylos, Ledum, Cassiope, Lwpinus, Geranium, EpiloMum, 

 Silene, Brdba, Saxifraga. Masses of Empetrum nigrum, a Bryanthus, and three species of Vaecinium 

 tiuge parts of the slopes with their colors. 



The list of mammals peculiar to or having their center of abundance in this district is a short 

 one, but all are notable species. The Sea Otter {Enhydra marina) and the Fur Seal (Callorhinus 

 ursinus) are the two most valuable fur-bearing animals in America. The latter, with the Sea Lion 

 {Eumetopias stelleri), are eminently characteristic of this district, where their breeding grounds are 

 situated. The birds more or less characteristic of this district are not very numerous, as the bleak 

 and rugged islands, swept by frequent gales and washed by two tempestuous seas, offer few 

 attractions for land birds. 



Widely separated from the mainland and surrounded by peculiar climatic conditions We would 

 look for certain modifications of form among the resident land birds. This is the case in every 

 instance, and Troglodytes alascensis, Leueosticte griseonucha, Melospiza cinerea, Lagopus rupestris 

 nelsoni, and Lagopus rupestris athhensis are all resident and peculiar forms, with Tringa ptilocnemis 

 and Ammodramus sandwichensis, similarly modified and breeding there, but which are known to 

 winter to the southward. 



The sea-fowl surrounding these islands, and having their summer, and sometimes winter, head- 

 quarters within the limits of this district, are Bissa brevirostris, Larus schistisagus, Brachyrhamphus 

 Mttlitzii, B, marmoratus, Simorhynchus pygmceus, SynthliborhampUus antiquus, 8. wumizusume, 

 Biomedea albatrus, Oceanodroma furcata, Fulmarus glacialis rodgersii, F. glaeialis glupischa. 



All of these water birds are known to extend their breeding range beyond the limits of this 

 district, and Larus schistisagus, with Fulmarus glacialis glupischa, probably have their center of 

 abundance on the Asiatic coast, but are common in Alaska ouly in this district. 



In examining the land birds of this district, including Arquatella ptilocnemis, the most notice- 

 able peculiarity of the insular varieties appears to be a more robust and stouter form as compared 

 with their mainland congeners. There is also a difference in coloration, which is usually darker on 

 the island forms, excepting the races of the Sitkan district. This darkening of the colors of birds 

 on the Aleutian Islands is toward gray shades, in distinction from the rufous exhibited in the 

 Sitkan district. The Aleutian land birds exhibit an increase in the length of the bill without a 

 proportionate thickening of the same. The cause of the more robust physique of the land birds 

 of this district as compared with their mainland relatives appears in the constant struggle for 

 existence they must maintain in a most inclement climate and against the high winds that prevail. 

 As to some extent illustrative of the conditions that attend bird life here I may cite the first view 

 I had of Troglodytes alascensis. It was on Akoutan Island, and so fierce a gale was blowing that I 

 had difBculty at times in keeping my feet; yet on the crest of a steep cliff-like slope, in the very 

 teeth of the gale, one of these birds clung securely to a small dwarf willow and sang lustily at 

 short intervals, unmindful of the fierce wind and wintry landscape about him. One of the weaker 

 mainland relatives of this bird, in such a wind, must inevitably have been dashed from his perch 

 and driven far out to sea to perish miserably, as do so many land birds each year. 



The aborigines of this district are as characteristic as any of the faunal divisions. The natives 

 are the Aleut branch of the Eskimos and are the most widely differentiated of any branch of that 

 great family. 



(3) Alaskan Arctic Disthict. 



This district covers the treeless coast belt, varying in width from 3 or 4 to 100 miles (except 

 where the trees reach the coast at the head of Norton Sound), which extends from the peninsula 

 of, Aliaska through Bering Straits and around the Arctic shore to the mouth of the Mackenzie Eiver, 

 including the islands of Bering Sea and straits north of the Fur Seal group. To set forth the 

 characteristics of this district more clearly, I have grouped the birds under two heads; first, those 

 having their center of abundance and their breeding ground here; and second, those species 

 which are found as stragglers from other regions but occur nowhere else in Alaska, or but rarely 

 Dutside these limits. The islands of this district are low and rocky, except those in Bering Straits, 

 which are small and rise precipitously from the sea; they are all barren and forbidding in appear- 



