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THE MONTHLY BULLETIN. 



claws blackish-brown, horn-color at tips ; soles of hind feet naked nearly to 

 heel. Chin and throat and insides of forelegs and thighs buff y white ; belly with 

 hairs extensively slaty brown at base, tipped with whitish ; in other words, whitish 

 with much slaty brown showing through. Tail well-haired, flat in form, broadest in 

 middle portion, tapering somewhat toward end ; in color, as viewed from above, 

 chiefly black, with a margin of ochraceous-buff ; there is considerable mixture with 

 cinnamon-brown toward base, however, and separation of the hairs discloses the 

 deeper-lying hazel color of their roots ; lower surface of tail centrally solid hazel, pal- 

 ing to ochraceous-tawny at base of tail, then a zone of black, and then an outer fringe of 

 bright ochraceous-buff. The body side-stripes are sharply defined along their edges, 

 but at their ends fade out gradually ; also the reddish of head blends by degrees with 

 colors of body adjacent. 



Color variations. — As far as we can see there is no difference in coloration 

 between male and female, in spite of the extraordinarily bright pattern of coloration 

 in this species. The young, even third-grown ones, are very similar to the adults in 

 pattern, the difference consisting only in paler tones of color, especially about the 

 head. There is, however, considerable change in the depth of coloration with season. 

 In the spring and early summer the head region is much paler than in late summer 

 and fall, and there is much other evidence of fading and wear to which the pelage 

 has been subjected. In June specimens the head is pale cinnamon-buff. 



As far as we can determine from the collection of specimens studied there is but 

 one thorough-going molt each year and this takes place in June and July. The 

 process is gradual. The exchange of old hair for new begins first on the head and 

 progresses backwards ; but specimens often show a patchy coat, with areas of dense 

 new hair on the head or back surrounded by old worn hair. 



We are unable to make out a distinguishable race from the Tr'nity Mountain 

 region, trinitatis of Merriam, 1901, p. 126, type from "Trinity Mountains east of 

 Hoopa Valley, California (altitude 5,700 feet)." The characters assigned, of color 

 and size, are not borne out in our large series of specimens from the Trinity region 

 as compared with series from the northern Sierra Nevada. There is, however, a 

 slight tendency towards paling of colors in chrysodeirus at the southern end of the 

 Sierra Nevada and along their east flank ; for example, as shown by specimens from 

 the east declivity of Kearsarge Pass, west of Independence. This modification is 

 evidently in the direction of perpallidus. 



Measurements. — Average and extreme measurements, in millimeters, of twenty 

 full-grown specimens from the west slope of the high central Sierra Nevada are as 

 follows: Ten males: total length, 272 ( 253-290) ; tail vertebra?, 89 (75-104) ; hind 

 foot, 41 (38-43) ; ear from crown, 15.7 (11.0-19.0) ; greatest length of skull, 44.0 

 (42.2-46.2) ; zygomatic breadth, 26.6 (25.2-28.2) ; interorbital width, 10.4 (9.5-11.1). 

 Ten females: total length, 266 ( 243-285) ; tail vertebrae, 83 ( 67-100) ; hind foot, 

 41 (39-44) ; ear from crown, 16.1 (13.0-21.0) ; greatest length of skull, 42.7 

 (41.0-44.1) ; zygomatic breadth, 25.9 (25.0-27.1) ; interorbital width, 10.3 (9.2-11.0). 



It would appear from the above figures that in males the tail averages a little 

 longer than in females. The skulls of old individuals, particularly males, relative age 

 being estimated by degree of wear on the crowns of the molar teeth, show greatest 

 size, particularly as regards zygomatic breadth and heaviness of rostrum. Old 

 skulls also show wider brain-case, broader jugals, and stouter postorbital processes. 



Weights. — Average and extreme weights, in grams, of twenty full-grown speci- 

 mens from the west slope of the high central Sierra Nevada are as follows : Ten 

 males, 181 (155-218); ten females, 199 (136-245). Averages, in ounces: males, 

 about 6i ; females, about 7. 



The heaviest example (245 grams) was a pregnant female. Males average heavier 

 in the fall, when they are fat, than in early summer. 



Type locality. — Fort Klamath [mountains near], Klamath County, Oregon (Mer- 

 riam, 1890, p. 19). 



Distribution area. — Upper coniferous belt (Canadian and Hudsonian life-zones, 

 less commonly down into Transition) along the Sierra Nevada, south as far as 

 Cannell Meadows, in extreme southern Tulare County ; north through the Mount 

 Lassen country to Mount Shasta, and thence west through the Trinity, Scott and 

 Salmon Mountains (Mus. Vert. Zool.) to extreme eastern Humboldt County (Mer- 

 riam, 1901, p. 126) ; also on the Siskiyou Mountains, along the Oregon border of 

 western Siskiyou County (Merriam, 1901, p. 126) ; on the mountain mass to the 



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