192 NORTH AMERICAN FAUNA [No. 55 



CLETHRIONOMYS CALIFORNICUS OBSCURUS (MERRIAM) 



DUSKY REEHBAOKED MOUSE 



Evotomys obscurus Merriam, Biol. Soc. Wash. Proc. 11 : 72, 1897. 



Type. Collected at Prospect, upper Rogue River Valley, Oreg., by Edward A. 

 Preble in 1896. 



General characters. This is a smaller, lighter colored interior form of cali- 

 fornicus, with red of back less obscured. Back of adults light chestnut brown, 

 not much obscured by black hairs; sides dull buffy gray; belly buffy gray; 

 feet whitish or gray with whitish toes ; tail but slightly bicolor. Young darker, 

 duller, and more plumbeous. 



Measurements. Average of typical adults : Total length, 144 mm ; tail, 44.5 ; 

 foot, 18.2; ear (dry), 10. 



Distribution and habitat. These rather dull-colored little rodents 

 are shown by the present series of specimens to be intermediate be- 

 tween calif ornicus and mazama, not only in characters but in distri- 

 bution, occupying the more open Transition Zone valleys between the 

 heavy timber of the humid Coast Ranges and the Canadian Zone 

 forests of the Cascades, and extending from northern California up 

 through the edges of the Rogue, Umpqua, and Willamette River 

 Valleys in Oregon (fig. 40). They are generally found in the 

 woods under old logs or stumps or dense vegetation in either wet or 

 dry situations. 



General habits. Apparently little is known to distinguish the 

 habits of these from calif ornicus, except that they are generally in 

 less dark and gloomy forests. At the type locality, Prospect, on the 

 upper waters of Rogue River, Preble took two specimens in damp 

 mossy and grassy places near the river. At Grants Pass, Streator 

 took one under a log in the edge of the woods back a mile from 

 town, and in the Siskiypu Mountains, Hollister trapped a few in 

 damp fir forests and one in a mountain beaver runway. At the west 

 base of Mount Jefferson, Loring took a series of specimens under 

 logs, stumps, brush heaps, and rocks in the dry woods at some dis- 

 tance from streams, using rolled oats and bacon for trap bait. 



CLETHRIONOMYS CALIFORNICUS MAZAMA (MEKRIAM) 

 MAZAMA RED-BACKED MOUSE 



Evotomys massama Merriam, Biol. Soc. Wash. Proc. 11 : 71, 1897. 



Type. Collected at Mount Mazama, south side of Crater Lake, Oreg., by C. 

 Hart Merriam and Vernon Bailey. August 15. 1896. 



General characters. Large, but smaller than californicus, about as in o&- 

 scurus, colors brighter and clearer than either. Back of adults light hazel in 

 a fairly well-defined area ; sides light buffy gray ; belly washed with buffy over 

 plumbeous; feet white or whitish; tail sharply bicolor, sooty above, whitish 

 below. Young darker, more plumbeous. 



Measurements. Average of several typical adults: Total length, 157 mm; 

 tail, 52; foot, 18.75; ear (dry), 11. 



Distribution and habitat. This is a boreal mountain form, occupy- 

 ing apparently all the Canadian Zone area of the Cascade Mountains 

 in Oregon and of Mount Shasta in California, grading into obscurus 

 on the lower slopes (fig. 40) . 



General habits. These bright-colored little animals are generally 

 caught under logs or around stumps and hollow trees in the open 



