90 MILLER 



nearly to base o£ tail. Ears colored like dorsal stripe. Sides an 

 indescribable grizzle of hair brown, whitish, black, and slate color, 

 the general effect clear light gray. Whole underparts soiled buffy 

 white, darkened by the slaty bases of the hairs, which show through 

 irregularly on the surface, especially when the fur is disarranged. 

 Cheeks, muzzle, and sides of head similar to sides of body, but slightly 

 darker. Tail sharply bicolor, brownish above, dirty white below. 

 Feet dirty white. 



In a half-grown specimen from Finmark, Norway, loaned by Mr. 

 Robert Collett, the dorsal stripe is bister scarcely tinged with red 

 except in the region between the ears. Here it is dull russet. Other- 

 wise the coloring is essentially as in the adult. 



Sktill. — The skull of Evoto7nys 7-ufocanus has the general appear- 

 ance of that of a medium sized Microtus with teeth slightly weaker 

 than usual. Braincase relatively deeper than in Microtus agrestis 

 from Upsala, Sweden, slightly longer than broad, squarely truncate 

 posteriorly, its outline carried squarely forward by the large postor- 

 bital processes. It is strongly marked by ridges for muscular attach- 

 ment. Interorbital region narrow, with a deep longitudinal median 

 furrow. Rostral protuberances ^ smaller than in the species of true 

 Evoto7nys and placed close to root of zygomatic process of maxillary. 

 Rostrum short, deep, and heavy. Palate and ventral aspect of skull 

 much as in Evotomys iiorvegicus except for the relatively larger* 

 teeth and audital bullae, the latter even larger than in Microtis agrestis. 



Measurements of an adult skull from Tanen, Postanger, Finmarken, 

 Norway: Greatest length 26; basal length 26; basilar length 25; 

 zygomatic breadth 15.4; mastoid breadth 13.6; interorbital con- 

 striction 4; diastema S ; palatal length 13 ; occipital depth (in median 

 line) 7.6; frontopalatal depth (at middle of molar series) 7S ; mandi- 

 ble 17; maxillary toothrow (alveoli) 6.S ; mandibular toothrow 

 (alveoli) 6. 



Teeth. — The teeth of Evotomys riifocamis as compared with those 

 of other members of the genus * are chiefly remarkable for their large 

 size, gi"eat strength, and sharply pointed salient angles. In robustness 

 the teeth perhaps slightly surpass those of an adult Microtus agrestis 

 from Upsala, Sweden, though this appearance may be due to the 

 broader dentine spaces. It is especially noticeable in the mandilnilar 



'See Proc. Acad. Nat. Sci., Philadelphia, 1S9S, p. 361. 



2 Amoug the Europeau nicuibers of the subgenus Evoioviys^ I can find no 

 tangible differential characters in the teeth. In the larger species the teeth are 

 slightly larger than in the smaller ones ; but the proportions and the pattern of 

 enamel folding remain the same. 



