The American Voles of the Genus Evotomys. 133 



Evotomys obscurus Merriam. 



Evotomys obscurus Merriam, Proc. Biol. Soc. Wash., vol. XI, p. 72, April 

 21,' 1897. 



Type locality. Prospect, Upper Rogue River Valley, Oregon. 



Geographic distribution. West slope of the southern Cascade Range and 

 northern Sierra Nevada in southern Oregon and northern California. 



General characters. A. rather large, grayish species, with small gray ears 

 and indistinct markings ; side glands inconspicuous, but easily discovered 

 on blowing apart the fur. The characters given are mainly those distin 

 guishing the species from E. mazama. 



Color. Upper parts olive gray, with an ill defined dorsal area of cin 

 namon rufous, obscured by black hairs ; lower part of sides and face clear 

 gray ; belly washed with dull buff; ears dusky, not rufous tipped ; feet 

 dusky gray ; tail distinctly bicolor in specimens from the type locality, 

 more sharply bicolor in specimens from Carberry Ranch, California. 



Cranial characters. Skull less angular and abruptly spreading than that 

 of E. mazama and with a more arched dorsal line ; rostrum short, de- 

 curved, with lower outline well arched; incisive foramina short and 

 wide ; palatines and audital bullae as in E. mazama. 



Measurements. Type specimen, measured in the flesh by E. A. Preble: 

 total length, 155; tail vertebr&e, 47; hind foot, 17. Skull of type: basal 

 length (basion to gnathion), 21.8; zygomatic breadth, 13.3; mastoid 

 breadth, 11.5; alveolar length of molar series, 4.5. 



Remarks. The series of specimens includes both young and adult indi 

 viduals collected in May, August, September, and December, but appar 

 ently none in full winter pelage. In both geographic position and specific 

 characters this species lies between E. mazama of the summit of the Cas 

 cades and E. californicus of the coast region. On the side of Mount 

 Mazama it almost or quite meets the range of E. mazama, with which 

 none of the specimens show evidence of intergradation. Specimens from 

 Carberry Ranch show a slight approach toward californicus, and future 

 collections may prove obscurus to be a lighter-colored, interior form of that 

 species. 



Specimens examined. Total number, 10, from 5 localities: 



Oregon : Prospect, 4 ; west side of Crater Lake, 1 : Grand Pass, 1 ; 



Siskiyou, 1. 



California: Carberry Ranch (near Montgomery Creek), Shasta 

 County, 3. 



Evotomys californicus Merriam. 



Evotomys californicus Merriam, North American Fauna No. 4, p. 26, pi. ii, 

 fig. 2, Oct. 8, 1890. 



Type locality. Eureka, Humboldt Co., California. 



Geographic distribution. Coast strip of Oregon and northern California. 



General characters. One of the largest, darkest, and longest-tailed species 



in North America. Dorsal area ill defined ; ears small, and in May and 



