276 MICEOTIN^ 



Characters. — Size large (hind-foot 21 mm. ; basal length of 

 skull 22-8 mm.), tail long, nearly half the length of head and 

 body, colour dark. 



Upper parts dark bistre or sepia, becoming dusky on rump, 

 and dull, dark chestnut on back ; mantle indistinct, shading 

 gradually into colour of sides ; belly pale bufEy or soiled whitish 

 darkened by under fur. Lateral glands conspicuous in old males, 

 covered by oval patches of shghtly contrasted dense fur. Ears 

 dusky, with no rufous or light-coloured hairs. Feet whitish or 

 but slightly dusky. Tail sharply bicoloured, blackish above and 

 at tip, whitish below. 



Skull thick and heavy, with short stout decurved rostrum; 

 zygomatic arches bent well down and not abruptly spreading; 

 palatines usually triangular in outline, instead of U-shaped as 

 in other species, and with a triple or single-pointed posterior 

 projection. Auditory bullae and pterygoids both relatively and 

 absolutely larger than in any other species. 



Cheek-teeth wide and heavy; enamel folds crowded longi- 

 tudinally and irregular ; m^ short with posterior loop very small 

 or, in four specimens out of six, absent. 



For external and cranial measurements, see table at end of 

 volume. 



37. Evotomys occidentalis Merriam. 



1890. Evotomys occidentalis Merriam, N. Amer. Fauna, No. 4, p. 25; 



BaUey, Proc. Biol. Soc. Washington, 11, p. 134, 1897; Miller, 



" List," 1912, p. 213; " List," 1924, p. 404. 

 1894. Evotomys pygmceus Rhoads, Proc. Acad. Nat. Sci. Philadelphia, 



p. 284; described from the mouth of the Nisqually River, Pierce 



County, Wasliington ; type : Rhoads Collection No. 247 ; young 



female. 



Type.~V.S. Nat. Mus., No. ^^^; adult male, collected 

 August 16, 1889, by T. S. Palmer. ' 



Type locality. — -Aberdeen, Chehalis County, Washington. 



Range. — Coast and Puget Sound region of Washington and 

 southern British Columbia. 



Characters. — Size considerably less than in E. calif ornicus; 

 dorsal area ill defined, sometimes indistinct, varying from dull 

 burnt umber to dark chestnut, darkened by numerous black- 

 tipped hairs. Sides dusky grey with a buffy suffusion, an oval 

 darker patch over lateral glands. Belly saliaon buff, darkened 

 by hair bases. Ears concolorous with back, nearly naked, not 

 large, but conspicuous above short summer fur. Feet dusky. 

 Tail almost concolorous, blackish. 



Skull thin and light, without prominent angles and processes, 

 relatively narrow and slender, with gently arching zygomata; 

 palatines with a rounded or notched posterior projection; 

 pterygoids flat, thin, and much perforated at base. Auditory 

 bullae much inflated, crowding close together over basioccipital. 



