1904.] Allen, Mammals from Alaska. 281 



Peninsula, where it was abundant, and it seems to be equally 

 abundant on the Kenai Peninsula, where it was found at all 

 points where collections were made. There is no appreciable 

 difference between specimens from Muller Bay and the Kenai 

 Peninsula. There was, as would be expected, a much higher 

 proportion of adults in the Muller Bay series, taken in May 

 and early June, than in the Kenai series, taken much later 

 in the season. In the former about one half were adult, and 

 in the latter only about one fifth. The Muller Bay adults 

 measure as follows: 20 males, total length, 174.5 (160-192, 

 with only two above 184) ; tail vertebrae, 41 (38-50, with only 

 two above 45); hind foot, 21 (20-22); ear, 12 (11-13) :i8 

 females, 168 (155-180); 40.7 (36-50, only two above 45); 

 20.6 (20-21); 12 (11-13). 



At Muller Bay, says Mr. Anderson, "the runways of this 

 animal were seen almost everywhere I went, especially in the 

 lowlands in places where the soil was not moist. . . . Dur- 

 ing our stay at Muller Bay almost every adult female obtained 

 was found to have from six to eight embryos." In Seldovia 

 it was found " most abundant in some coarse grass growing 

 beside a salt-water slough near the village. In this they had 

 burrows and long distinct runways. Their runways were also 

 often found in the more common grass which grows in most 

 openings, and numbers were trapped in such places." 



1 1 . Synaptomys dalli Merriam. BALL'S LEMMING MOUSE. 

 Sixty-six specimens, taken as follows: Seldovia, 40, June 27- 

 August 3; Sheep Creek, 12, August 14-26; Barabori, 2, 

 August 30; Caribou Camp, 5, Sept. 7-9; Moose Camp, 7, 

 Sept. 25-Oct. 5. About one third are adults, of which only 

 4 are females, 15 being males. They measure as follows: 15 

 males, total length, 130 (124-134); tail vertebrae, 23.7 (21- 

 25); hind foot, 19.3 (19-21); ear, 13.7 (12-15): 4 females, 

 132 (129-134); 25.5 (24-27), 19 (18-20), 12.5 (13-14). The 

 females average larger than the males, but they are also 

 obviously older than the average of the males, the difference 

 in size being evidently due to difference of age. 



At Seldovia this species was found " most frequently in 



