1908.] MAMMALS. 177 



yellowish-white below, and in two individuals slightly albinistic at 

 the tip. Ten individuals of both sexes average: Total length 397, 

 tail vertebra' 177, hind foot 40. 



Phenacomys mackenzii Preble. Mackenzie Phenacomys. 



Phenacomys mackenzii Preble, Proc. Biol. Soc. Wash.. XV, p. L82. August 

 6, 1902. (Fort Smith, Mackenzie.) 



One of the gratifying results of our work in the Athabaska and 



Mackenzie country was the detection of Phenacomys, represented by a 



new form, as an inhabitant of the region, the genus thus being for 

 the first time ascertained to occur in the interior north of Alberta. 



In 1001 we first trapped this vole at our camp on Slave River 10 

 miles below the mouth of the Peace, on June 11. taking an adult 

 female in poplar woods. We next took the species at Fort Smith. 

 where, during the last few days of June, a series of 25 specimens 

 was trapped. They were captured in a strip of spruce and poplar 

 woods bordering a marsh, the situation being dry, however, since 

 the ground sloped gently from an adjacent poplar ridge. No run- 

 ways or burrows were found which could be attributed with certainty 

 to this species, since both Microtus and Evotomys were abundant and 

 were taken in the same traps. Embryos, varying in number from 

 4 to 7, were noted in several instances, and a number of half-grown 

 young ones were trapped. Many were taken beneath the clumps of 

 buffaloberry (Lepargyrcea canadensis) which helped to form a sparse 

 undergrowth. \Ye took a few specimens in similar situations at Fort 

 Resolution early in July, and my brother trapped one on Mission 

 Island near by. 



In this series the fur of the upperparts is dark plumbeous at base, 

 tipped with yellowish-brown, black, and gray, the varying propor- 

 tions of these colors causing some variation in the general color of the 

 different specimens; face from the eyes forward, ochraceous; cheeks 

 and underparts grayish-white, grading insensibly into color of upper 

 parts. Ten adults of both sexes from Fort Smith average: Total 

 length 110.7, tail vertebrae 32.7, hind foot 17. 



During my trip northward from Great Slave 1 Lake in 1903 I 

 trapped an adult male near the shores of a small lake a few mile- 

 north of Lake St Croix. 120 miles slightly west of north of Fort Rae. 

 This individual was taken in dry mixed woods of spruce and birch. 

 It measured: Total length 127, tail vertebrae 31, hind foot is. The 

 skull unfortunately was lost, but the skin can be exactly matched 

 by specimens in the series from Fort Smith, the type locality of 

 P. mackenzii, and is certainly referable to this species. In Septem- 

 ber of the same year Alfred E. Preble and Merritt Cary took two 

 specimens in mossv spruce woods on the Athabaska at points 5 and 



441 :n — N( >. i'7— OS 1 L' 



