150 University of California Publications in Zoology [Vol.30 



Neotoma cinerea saxamans Osgood. Northern Bushy-tailed Wood Rat 

 Three specimens collected (nos. 34432-34434), one at Atlin and two 

 at our camp on lower Otter Creek. In this region, as elsewhere in the 

 northwest, the wood rat is more or less of a pest, invading cabins and 

 destroying or carrying away almost anything that can be moved. We 

 sa-w slight trace of the presence of this species, however, and it seems 

 likely that the wood rats had suffered temporary reduction of numbers 

 together with other small rodents. 



Synaptomys borealis dalli Merriam. Dall Lemming Mouse 

 One specimen (no. 34435), a young male, was trapped on upper 

 Otter Creek (3800 feet altitude), on July 30. The species was not 

 otherwise encountered. 



Microtus drummondii (Audubon and Bachman) 

 Drummond Meadow Mouse 

 Fourteen specimens were preserved (nos. 34436-34449), thirteen 

 from the vicinity of Atlin and one from the summit of Spruce 

 Mountain (5000 feet altitude). They were rare, one specimen in two 

 or three nights being the most to be hoped for in a line of twenty-five 

 or thirty traps. 



Microtus mordax mordax (Merriam). Cantankerous Meadow Mouse 

 Nine specimens were collected (nos. 34450-34458), four from Atlin, 

 four from Otter Creek (3000 to 4000 feet altitude), and one from 

 near the summit of Spruce Mountain (5000 feet altitude). These nine 

 specimens represent approximately the result of eighty traps set out 

 for two weeks. Not that just that number of traps was set for exactly 

 that number of days at any one period, but that would be about the 

 sum total from traps placed where Microtv^ should have been trapped. 

 Two pregnant females contained three and four embryos, respectively. 

 In an extensive series from the upper Stikine River, trapped when the 

 animals were abundant, the number of embryos was usually five, or 

 six. 



Ondatra zibethica spatulata (Osgood). Northwestern Muskrat 

 Muskrats were seen at various times in ponds at the edge of the 



town of Atlin, and elsewhere in suitable places east to Lake Teslin. 



The species is abundant throughout this whole region. 



