1^11] Swarth: Alaska Expedition of 1909. 125 



as compared with 22 to 23.5 in the former. One of the two 

 specimens taken on Kuiu Island (no. 8485) also exceeds in 

 every respect the maximum measurements ascribed to hylaeus by 

 Osgood (1909, p. 54), its dimensions being as follows: length 

 213 mm., tail vertebrae 120, hind foot 24. 



The Kupreanof mice, in cranial characters, resemble those 

 from Prince of Wales less closely than do those from Admiralty 

 Island, curiously enough considering their intermediate geograph- 

 ical position. The skulls of Admiralty specimens are indistin- 

 guishable from those from Prince of "Wales Island, whereas those 

 from Kupreanof are appreciably longer and more slender. 

 Specimens from Mitkof Island in their slightly larger size show 

 an approach to macrorhinus, as previously noted by Osgood 

 (1. c). The single example secured on Zarembo Island (no. 

 8560) is apparently to be referred to hylaeus. Those taken on 

 the mainland at Thomas Bay, Port Snettisham, and the Taku 

 River, are apparently all of this form. The single adult secured 

 on the Taku (no. 8591) is rather large for hylaeus, but no more 

 so than the Kuiu Island specimen mentioned above. 



One specimen from Dall Island is abnormally colored in 

 exactly the same manner as an example of macrorhinus described 

 by Osgood (1. c, p. 57, footnote). This mouse (no 8497 ? Rocky 

 Bay, Dall Island, May 31, 1909) has the entire under parts rich 

 brown, similar to the sides. The hind feet are grayish, and the 

 front feet white, while there are small white spots on the lips 

 and on the center of the throat. 



Although white-footed mice were taken at most of the places 

 where we collected, there were but a few points where they were 

 really abundant. As observed in this region, hylaeus and mac- 

 rorhinus were exactly alike in habits and mode of life, and both 

 seemed rather to favor the littoral zone. A beach well strewn 

 with large drift logs, trees, etc., and thus affording plenty of 

 shelter, was quite sure to yield a harvest of mice. Another place 

 where they could generally be found was in the vicinity of cabins 

 or human habitations of any sort, occupied or deserted, such 

 dwellings in this region being almost invariably placed just 

 above tide water. Elsewhere in the woods or meadows, it was 

 a mere chance to secure them. 



