1908.] 



MAMMAI.S. 



177 



veUowish-white below, and in two inclividnals slightly albinistic at 

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

 tail vertebra? 177. hind foot J:6. 



Phenacomys mackenzii Preble. Mackenzie Phenacomys. 



Phenaconujs mackenzii Preble, Proc. Biol. Soc. Wasli., XV, p. 182. 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 Elver 10 

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

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

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

 was trajoped. 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. Xo run- 

 ways or burrows were found which could be attributed with certainty 

 to this species, since both Microtus and E rotomys were abundant and 

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

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

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

 biilfaloberi-y {Lepargyra-a canadnisJs) which helped to form a sparse 

 undergrowth. AVe took a few >pcciiiu'ns in similar situations at Fort 

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

 Island near by. 



In thi- >eries the fur of the upperparts is dark plumbeous at base, 

 tipped with yellowish-brown, black, and gi^ay, the varying propor- 

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

 different specimens; face from the eyes forAvard. ochraceous; cheeks 

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

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

 length 140.7, tail vertebrae 32.7. hind foot 17. 



During my trip northward from Great Slave Lake in 1903 I 

 trapped an adidt male near the shores of a small lake a few^ miles 

 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 18. 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. machenziu and is certainly referable to this species. In Septem- 

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

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



441.31— No. 27—08 12 



