1908.] 



MAMMALS. 



179 



Sk'ulJ. — Only one skull of typical E. gap peri (from Emsdale, 

 Ontario) is available for comparison. Compared with this the skulls 

 of E. g. afhahasca' are longer, with a less rounded braincase and 

 slightly larger bullae, but of course it is inadvisable to attempt to for- 

 mulate cranial characters on such scanty material. For an opportu- 

 nity to compare this form with skins of typical E. gapperi^ I am in- 

 debted to Gerrit S. Miller, jr., who loaned me a series of Evotomys 

 collected at Xorth Bay. Lake Xipissing, Ontario. They were taken in 

 August and are therefore in comparable pelage. As would be ex- 

 pected from its more northern habitat, the fur of E. g. athabascce is 

 longer and fuller than that of E. gap pen. The skidls of the Xorth 

 Bay series are unfortunately not available. 



AVe foinid this vole common throughottt the region north to Great 

 Slave Lake and secured a very large series, comprising specimens 

 from points on the Athabaska 5 and 80 miles above Athabaska Land- 

 ing: Galling Eiver: Swift Current: 50 and 100 miles above Pelican 

 Kapid : Pelican Rapid ; Cascade Rapid ; Mountain Rapid ; Fort 

 Chipewvan : Slave River at the motith of the Peace, and at otir 

 cam2)s 10 and 25 miles below that point ; Smith Landing : Fort Smith; 

 and Fort Resolution. 



In 1001 we found the species very common at our various camps 

 near Fort Chipewvan and easily sectired a large series. Here we 

 found the animals living mainly in the sprtice Avoods growing in 

 valleys and ravines, though some were catight in swamps and in 

 mixed Avoods on higher ground. It seemed to be common also along 

 Slave River between Fort Chipewyan and Fort Smith, and a large 

 series was trapped at the latter place. The species was abundant in 

 a strip of mixed woods bordering a marsh half a mile south of the 

 post, and here most of our specimens were secured. In the hurried 

 work between Fort Smith and Fort Resolution, it was not taken. It 

 was fairly common in the vicinity of the latter post, however, where 

 Alfred E. Preble secured a good series of specimens, mainly on Mis- 

 sion Island, which is better adapted to its habits than the mainland 

 because the woods have not been so mtich devastated by cutting and 

 by fire. In the autumn of 1903 the species was found to be abun- 

 dant at various points along the Athabaska by my brother and Gary, 

 and a large series in the normal phase was secured. 



Ten adults of both sexes from Fort Chipewyan average : Total 

 length 115.G. tail vertebrae 40.6, hind foot 18: ten from Fort Smith 

 average : 112, 38, 18 ; ten from Fort Resolution, 142.7, 38.5, 19. 



The slaty or gray phase of color, hitherto tmrecorded from this 

 region north of south-central Alberta, was taken at the following 

 localities: Slave River. 10 miles below mouth of Peace (1) ; 25 miles 

 Ijelow mouth of Peace (1) ; Smith Landing (1) ; and Fort Smith (6). 

 At these places this phase was represented by less than 10 percent of 



