210 NORTH AMERICAN FAUNA [No. 55 



paler; belly washed with creamy white or smoky gray; feet plumbeous; tail 

 blackish above, grayish below. 



Measurements. Average of adult topotypes : Total length, 177 mm ; tail, 64 ; 

 foot, 22; ear (dry), 12. 



Distribution and habitat. This brown form of the long-tailed 

 meadow mice occupies a narrow strip along the coast of southwestern 

 Oregon and northwestern California, usually in the marshes or low 

 fields, only little above high tide level (fig. 46) . 



General habits. In no important manner do the habits of these 

 mice appear to differ from those of typical mordaw. The animals are 

 numerous in the little marshes just back of the coast and sometimes 

 extend into the fields and meadows and brush land. At the mouth 

 of Rogue River the writer's line of 13 traps caught 11 of these mice 

 during the day, and only 5 more at night, which indicates rather 

 decided diurnal habits. 



MICROTUS MORDAX ABDITUS A. B. HOWELL 

 TILLAMOOK MEADOW MOUSE 



Microtus mordax abditus A. B. Howell, Jour. Mammal. 4 : 36, 1923. 



Type. Collected at Walker's Ranch, Pleasant Valley (8 miles south of 

 Tillamook), Oreg., by A. Brazier Howell, September 8, 1920. 



General characters. Large with very long tail and large hind feet, distin- 

 guished from its nearest relative, Microtus mordaa macrourus by relatively 

 larger hind feet, longer, narrower skull, and generally browner coloration. 

 From M. townsendii with which it may occur it is distinguished by slightly 

 longer tail, lack of conspicuous hip glands in adult males, and by radical group 

 characters shown in the skulls. September pelage, upper parts dark sepia 

 brown; lower parts light cinnamon or buffy gray; feet dusky; tail blackish 

 above, brownish below. Skull longer, narrower and more slender than in 

 macrourus, with narrower, more elongated audital bullae. 



Measurements. Type, adult male : Total length, 221 mm ; tail, 93 ; foot, 28.5 ; 

 ear (dry), 14. Skull of type: Basal length, 28; nasals, 8.5; zygomatic breadth, 

 16; mastoid breadth, 12.5; alveolar length of upper molar series, 7.2. 



Distribution and habitat. Ten specimens of this species are re- 

 corded by Howell from the type locality near Elaine, and from Ne- 

 tarts on the coast west of Tillamook (fig. 46). Two were caught in 

 a small roadside ditch filled with cattails, and others in salal thickets 

 bordering a small creek near the sea. Evidently they are scarce or 

 rare over western Oregon or others would have been taken by some 

 of the numerous collectors who have worked along the coast. 



MIOROTUS RICHARDSONI ARVICOLOIDES (RHOADS) 

 CASCADE MEADOW MOUSE; WATER VOLE 



Aulacomys arvicoloides Rhoads, Amer. Nat. 28 : 182, 1894. 



Ttype Collected at Lake Keechelus, Kittitas County, Wash., at 8,000 feet, 

 by Allan Rupert, September 1893. 



General characters. Largest of our meadow mice; tail long; incisors pro- 

 jecting; side glands conspicuous on flanks in old males; tubercles on soles 

 of hind feet only five; fur long and rather coarse. Upper parts dusky or 

 smoky gray; lower parts thinly washed with whitish over plumbeous under- 

 fur ; feet dark gray ; tail bicolor, dusky above, grayish below. 



Measurements. Average of typical specimens: Total length, 234 mm; tail, 

 81 ; foot, 29.3 ; ear (dry) , 13. Large old male, 261 ; 92 ; 30 ; 14. 



