318 NORTH AMERICAN FAUNA 61, FISH AND WILDLIFE SERVICE 



Lemmus trimucronatus: Lemming 

 Lemmus trimucronatus minusculus 



As might be expected, this mouse ventures out a considerable 

 distance on Alaska Peninsula. Its range is roughly shown by the 

 following specimens in the Fish and Wildlife Service collection : 1 

 from Chogiung, 11 from Kakhtul, 24 from Kakhtul River, 20 from 

 Chulitna River, 2 from Kokwok River, 2 from Kokwok, on 

 Nushagak River, 6 from Nushagak, and 5 from Chignik Bay. 

 The last mentioned show that further collecting will undoubtedly 

 show a greater distribution on the more westerly part of the 

 Peninsula. 



Dicrostonyx groenlandicus: Collared Lemming 

 Dicrostonyx groenlandicus rubricatus 



Lemmings that, for the present, are referred to this subspecies 

 are found throughout the length of Alaska Peninsula and Unimak 

 Island. The few specimens we have from the western part of 

 Alaska Peninsula and Unimak Island do not entirely agree in 

 color with the typical rubricatus coloration. 



These specimens suggest a strong tendency toward the gray 

 pelage of stevensoni from Umnak Island. But in view of the 

 variations in the characters of this lemming, and the small num- 

 ber of specimens at hand, it is difficult to state the relationships 

 of the lemmings in this interesting region. 



In 1925, when I visited the west end of Alaska Peninsula and 

 Unimak Island, an attempt was made to collect a good series of 

 specimens, but the lemmings were scarce that year and only four 

 were obtained on Unimak Island. They had their burrows on the 

 higher tundra and among the lava beds. 



Dicrostonyx groenlandicus unalascensis 



The lemming from Unalaska Island was described in 1900 on 

 the basis of skulls taken from owl pellets, and for a long time we 

 knew nothing of its external characters. Many attempts had 

 been made to trap specimens, and during our brief stops at 

 Unalaska in 1936 and 1937 we tried to obtain some, but without 

 result. We did find remains of these mice, however, in red fox 

 droppings. 



In 1931, Gilmore succeeded in trapping two specimens on Una- 

 laska Island, and he has described them in detail (1933, p. 257). 

 Apparently, this form, like the one on Umnak Island, does not 

 acquire a white winter coat. 



