228 PHENACOMYS. 



540. Phenacomys mackenzii Preble. 



Phenacomys mackenzii Preble, Proc. Biol. Soc. Wash., xv, 1902, 

 p. 182. 

 Mackenzie's Vole. 



Type locality. ' Fort Smith, Slave River (near Athabasca, Mac- 

 kenzie boundary line), Canada. 



Genl. Char. Similar to P. celatus and P. c. crasstis; cranial char- 

 acters different; interorbital beads prominent, nearly meeting in old 

 adults. 



Color. Above mixed black and gray, tips of hairs yellowish 

 brown, beneath grayish white; tail above brownish, beneath grayish 

 white. 



Measurements. Total length, 142 ; tail vertebrae, 34 ; hind foot, 17. 



541. Phenacomys constablii Allen. 



Phenacomys constablei Allen, Bull. Am. Mus. Nat. Hist. N. Y., 

 1899, p. 4. Elliot, Syn. N. Am. Mamm., F. C. M. Pub., 11, 

 1901, p. 169. Zool. Ser. 

 Constable's Vole. 



Type locality. Telegraph Creek, Yukon, Canada. 



Geogr. Distr. Known only from the type locality. 



542. Phenacomys longicaudus True. 



Phenacomys longicaudus True, Proc. U. S. Nat. Mus., 1890, p. 



303. Elliot, Syn. N. Am. Mamm., F. C. M. Pub., 11, 1901, 



p. 169. Zool. Ser. 

 Long-tailed Vole. 



Type locality. Marshfield, Coos County, Oregon. 



Geogr. Distr. Coast district of Oregon. Range unknown. 



543. Phenacomys albipes Merriam. 



Phenacomys albipes Merr., Proc. Biol. Soc. Wash., xiv, 1901, p. 



125- 

 White-footed Vole. 



Type locality. Redwoods near Areata, Humboldt Bay, Humboldt 

 County, California. 



Genl. Char. Large; tail long, scantily haired; anterior root of 

 zygoma sloping backward; jugal nearly parallel; nasals truncate 

 posteriorly ; bullae large ; interpterygoid fossa long ; palate with median 

 azygos process. 



Color. Above grizzled bister; head, shoulders, and sides washed 

 with brown, beneath grayish plumbeous washed with buffy; feet 

 white; ankles dusky; tail above dusky, beneath whitish. 



Measurements. Total length, 168 ; tail vertebrae, 62 ; hind foot, 19. 



