132 Bailrij — TJir American Vole.s of the (knus Evotomys. 



farther apart than in E. saturahts; aiidital bullfe long and laterally ap- 

 pressed ; basioct'ipital wide l>etween IniUaj ; incisors pale ^vellow. 



Measurements. — Type, measured in flesh by Dr. C. Hart Merriani : total 

 length, 153; tail vertebrae, 48; hind foot, 20. Avei-age of 4 adults from 

 type locality measured by A. H. Howell : 148 ; 44 ; 20.2. Shdl of type : 

 basal length, 2o.5 ; nasals, 8; zygomatic breadth, 13.3; mastoid breadth, 

 11.6; alveolar length of upper molar series, 5.4. 



Remarks. — Three specimens from the Salmon River Mts. differ slightly 

 from the type, but the difference may be individual. Specimens of 

 E. sntiirafus from the Craig Mts., Idaho, and of E. gaJei from the Bear- 

 tootli Mts., Montana, though geographically near, show no close afhnity 

 with E. idahoensis. 



Specimens examined. — Total number, 15, from the two following localities : 



Idaho: Sawtooth or Alturas Lake, 12; Salmon River Mts., 3. 



Evotomys mazama Merriam. 



Evotomys mazama Merriam, Proc. Biol. Soc. Wash., vol. XI, p. 71, April 

 21," 1897. 



Type locality. — Crater Lake, Mt. Mazama, Oregon ; altitude, 7000 feet 

 [2130 meters]. 



Geographic distribution. — Crest of the Cascade Mountains in Oregon. 



General characters. — Large, long tailed, and bright colored; ears not 

 rufous; skull broad and angular; side glands conspicuous in all of the 

 adult males. 



Color. — Dorsal stripe extending from in front of ears to base of tail, cin- 

 namon rufous or hazel, shading gradually into huffy gray of sides and 

 face ; belly washed with bufiy white ; oval spot covering side glands slaty 

 gray, more or less frosted with white-tipped hairs ; feet grayish white ; 

 tail sharply bieolor, whitish below, l)lackish above. 



Cranial characters. — Skull angular, with unusually flat top, long, straight 

 rostrum, and abruptly spreading zygomata ; audita! bulUe large ; pterygoids 

 prominent, wide, and inflated at tlic tips; palatines rounded anteriorly, 

 with a median posterior projection ; enamel surface of incisors orange. 



Measurements. — Average of 4 adult males from type locality measured 

 by Dr. C. Hart Merriam: total length, 157; tail vertebra;, 52; hind foot, 

 18.7. Skull of type: basal length, 23.3; nasals, 7.2; zygomatic breadth, 

 14.2; mastoid breadth, 12.4 ; alveolar length of upper molar series, 5. 



Bemarks. — Erotomys mazama differs from E. saturatus in slightly larger 

 size and longer tail ; in yellower, less sharply outlined ^dorsal stripe ; no 

 tendency to white thi'oat patch ; in more angular skull with larger audital 

 bulhe and pterygoids ; in orange instead of pale yellowish enamel of 

 upper incisors, and most conspicuously in form of palatine bones. Fiom 

 the dark colored coast species it differs conspicuously in color, but with 

 E. obscurus it needs careful comparison. 



Specimens examined. — Total number, 19, from 2 localities: 

 Oregon: Crater Lake, 16; Mount Hood, 3. 



