The American Voles of the Genus Evotomys. 135 



General characters. Size considerably less than californicus ; dorsal area 

 indistinct; tail long and slender ; concolor ears nearly naked, not large, 

 but conspicuous above the short summer fur ; tail and feet scantily haired 

 in summer specimens ; lateral glands conspicuous in 2 out of 3 adults from 

 Aberdeen. 



Color. August specimens from Aberdeen : dorsal area ill denned, some 

 times indistinct, varying from dull burnt umber to dark chestnut, dark 

 ened by numerous black-tipped hairs ; sides dusky gray with a buffy 

 suffusion ; an oval patch of darker sooty gray covering side glands in the 

 type and two other specimens ; tail almost concolor, blackish ; feet dusky 

 or blackish ; belly salmon-buff, the dusky under fur showing through ; 

 nose blackish. 



Cranial characters. Skull thin and light, without prominent angles and 

 processes, relatively narrow and slender, with gently arching zygomata ; 

 anterior part of palate from molars to incisors well arched ; audital bullse 

 much inflated, crowding close together over basioccipital ; pterygoids flat, 

 thin, and much perforated at base; palatines with a rounded or notched 

 posterior projection ; molars normal ; anterior surface of upper incisors 

 orange, in strong contrast to the pale yellowish of those of E. sataratus. 



Measurements. Type, measured in the flesh by T. S. Palmer, $ ad.: 

 total length, 145; tail vertebrae, 45; hind foot, 18. Average of 3 adults 

 from type locality : 146 ; 47 ; 18.3. Skull of type : basal length, 22 ; nasals, 

 7 ; zygomatic breadth, 12.5 ; mastoid breadth, 11 ; alveolar length of molar 

 series, 4.7. 



Remarks. This species is peculiar to the low, moist coast and sound 

 region the ' Webfoot country' where its dark color blends with the 

 shadows of dense vegetation. In general the color is nearly as dark as 

 that of E. californicus, but the rich brown on the back, the concolor, 

 dusky tail, and dusky feet are the characters most sharply distinguishing 

 it from neighboring species. There is a possibility of intergradation with 

 E. californicus on the south, as well as with E. saturatus of the mountains 

 farther east. Specimens from Port Moody, B. C., while agreeing closely 

 with the type in all external characters, show a slight departure in cranial 

 characters in the more angular skull, paler incisors, and smaller audital 

 bullse. A half-grown specimen from the head of Cascade River is slightly 

 lighter and brighter colored than specimens of the same age from the type 

 locality. 



Evotomys pygmseus Rhoads, from the mouth of the Nisqually River, 

 Washington, is based on small size, and was described as the smallest 

 species of the genus, measuring 120; 34 ; 16. In a series of 9 specimens 

 from Tenino (16 miles SW. of the mouth of Nisqualla River), adult speci 

 mens, measured in the flesh by C. P. Streator, range from 136 ; 40 ; 18 to 

 155; 49; 18. Two not fully adult specimens from Steilacoom (8 miles 

 NE. of the mouth of Nisqually River) measure 125; 36; 16.5 and 128; 

 39 ; 17. In brief, specimens from Tenino and Steilacooni localities close 

 by and on both sides of the type locality of 'pygmseus' agree within the 

 limits of individual and slight seasonal variation in size, color, and cranial 

 characters with specimens from Aberdeen, the type locality of E. occiden- 



