Vol. XV, pp. 181-182 August 6, 1902 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTIONS OF NEW SPECIES OF STJ^fAPTOJIYS 

 AND PHENACOMYt^ FROM MACKENZIE, 



CANADA. 



BY EDWARD A. PREBLE. 



In studying a collection of mammals from the region of 

 Athabasca and Great Slave lakes, I tind the following forms of 

 ISynaptomys and Phenacomys which appear to be undescribed. 

 Neither of these genera has been previously recorded from this 



region. 



Synaptorays(Mictomys) bullatus sp. nov. 



2'ype from Trout Rock, near Fort Rae, Great Slave Lake, Macken- 

 zie, Canada. Skin and skull No. 110,632, $ ad., U. S. National Museum, 

 Biological Survey Collection. Collected August 17, 1901, by Edward 

 A. Preble. Original No., 4511. 



General characters.— '&\m\\sLV to Synaptomys {Mictomys) inmiitus, but 

 differing in cranial characters; closely resembling S. rfw?/i cranially, but 

 differing in color; hind foot small. 



Color. — Fur at base dark plumbeous, tipped with black and reddish- 

 brown, the black usually predominating on the back; sides lighter than 

 back; belly ashy-plumbeous, rather abruptly separated from the color 

 of sides; feet dusky brown; tail bicolor, dusky above, ashy beneath. 



Skull. — Compared with skviUs of Synaptomys {Mictomys) innuitus from 

 Labrador, skulls of bullatus differ as follows: skulls less flat, thezjgomatic 



35— Biol. Soc. Wash. Vol. XV, 1902. (181) 



