126 Bailey The American Voles of the Genus Evotomys. 



or less washed with huffy ; belly pure white or rarely creamy white ; 

 ears pale chestnut ; feet pure white; tail sharply bicolor, whitish below, 

 blackish brown above ; pencil black above, a few white hairs below. Adult 

 males with large whitish or light grayish spots over the side glands. 

 Summer pelage: dorsal stripe dark, rich chestnut; sides and face pale 

 bister, more or less suffused with yellowish ; belly thinly washed with 

 white or whitish ; feet dusky; tail darker and less sharply bicolor ; ears 

 brownish ; side spots in old males sooty gray. Young slightly darker 

 than adults. 



Cranial characters. Skull, compared with that of gapperi, smaller and 

 relatively narrower and slenderer ; even in old age not ridged or angular ; 

 audital bullte less rounded and inflated than in gapperi; posterior edge 

 of palate straight or slightly projecting on median line. 



Measurements. Average of 18 adults from type locality, measured in the 

 flesh by J. Alden Loring: total length, 123; tail vertebrae, 31.5; hind 

 foot, 17.9 ; tail, 25.5 per cent, of total length. Skull of type : basal length , 

 21.5 ; nasals, 6.8 ; zygomatic breadth, 12.8 ; mastoid breadth, 10.9 ; length 

 of upper molar series, 5. 



General remarks. There is no climatic or topographic barrier to prevent 

 Evotomi/s from ranging continuously from the type locality of gapperi to 

 all of the points from which loringi is known. Good series of specimens 

 from a chain of intermediate localities show direct connection, and prove 

 that the form to which the name loringi is applied has developed as it 

 reached out on the dryer, more open region along the edge of the prairies. 

 The extremes of the form come from the farthest outlying localities. 

 Specimens from the north shore of Lake Superior and thence westerly as 

 far as Tower, Minnesota, are fairly typical gapperi. Those from Hinckley 

 and Bridgman, near the middle of the State, are nearer loringi, while 

 Minneapolis and Elk River specimens are almost typical. Specimens 

 from Browns Valley, Minnesota, Fort Sisseton. South Dakota, and Port 

 land, North Dakota, are typical. Two from Pembina, North Dakota, are 

 doubtful, and one from Carberry, Manitoba, is clearly intermediate. 



Specimens examined. Total number, 56, from 10 localities (24 in the 

 Merriam collection, 32 in the Biological Survey collection) : 



North Dakota: Portland, 18; Pembina, 2. 



South Dakota: Fort Sisseton, 2; Travere, 2. 



Minnesota: Browns Valley, 5; Elk River, 5; Minneapolis, 7; Hinck 

 ley, 10 ; Bridgman, 4. 



Manitoba: Carberry, 1. 



Evotomys gapperi galei Merriam. 



Evotonv/s galei Merriam, North American Fauna, No. 4, p. 23, pi. ii, figure 

 3, October 8, 1890. 



Type locality. Ward,* Boulder County, Colorado. Altitude 9500 feet 

 (2900 meters). 



*The type locality was given in the original description as Gold Hill, 

 It has since been learned that the type specimen carcie from Ward, about 

 6 miles above Gold Hill. 



