VOL. XV, PP. 181-182 AUGUST 6, 1902 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



DESCRIPTIONS OF NEW SPECIES OF SYNAPTOMYS 



AND PHENACOMYS FROM MACKENZIE, 



CANADA. 



BY EDWARD A. PREBLE. 



In studying a collection of mammals from the region of 

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

 Synaptomys and Phenacomys which appear to be undescribed. 

 Neither of these genera has been previously recorded from this 

 region. 



Synaptomys (Mictomys) bullatus sp. nov. 



Type 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. Similar to Synaptomys (Mictomys) mnuitus, but 

 differing in cranial characters; closely resembling 8. datti 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. 



Skutt. Compared with skulls of Synaptomys (Mictomys} innuitus from 

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

 35-BioL. Soc. WASH. VOL. XV, 1902. (181) 



