352 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



the usual way and weighed 29 pounds avoidupois,. costing $1 a pound. 

 The fur was quite heavy, and was made into capes, muffs, and a coat, 

 which are still serviceable. The adult skins measured as follows: 

 1,090 by 700 mm., 1,060 by 720, 1,010 by 840, 970 by 780, 950 by 650, 

 940 by 770, 930 by 800, 930 by 700, 920 by 750, 900 by 770. Four 

 young of the year measured 760 by 600, 710 by 600, 670 by 580, 

 695 by 620. One in the second year measured 720 by 610. Two in 

 the third year measured 820 by 680, 810 by 720. As in all Arizona 

 beavers, the hides are thick and indurated, especially those of old 

 males that have many scars from fighting; and the coat is poorer in 

 quality and less dense than in northern skins. The fur, however, is 

 quite full and handsome. Ten^f these skins are of adults, taken be- 

 tween December and March, and stretched to a nearly perfect ellipse. 

 Of these. No. 168 (original number) is the largest, darkest, and hand- 

 somest, being in perfect winter pelage. The skin measures 930 by 800 

 mm., and weighs 2i pounds. There is an area of dark, reddish brown 

 extending from the forehead to the root of the tail, where the color 

 changes to a darker hue of shining vinaceous-chestnut, a lighter shade 

 of which extends to the under surface of the caudal peduncle and 

 inner surface of the thighs. The sides are rather uniform (slightly 

 reddish) fulvous. The underfur is of about the same color terminally 

 but grayish at the base of the hairs; that upon the dorsum is rich 

 brown. There is no ventral chestnut stripe in this specimen. 



The remaining nine adult winter specimens exhibit certain color 

 differences amounting to a considerable variation. No. 169 has the 

 dorsum paler and less reddish; the sides and belly are uniformly 

 brownish gray, with no tinge of red or fulvous, while the rump is paler 

 than the back, and more yellowish than in the above specimen, this 

 shading into dark vinaceous posteriorly and beneath. The skin 

 measures 1,090 by 700 mm. 



Between the extremes above described are various gradations 

 in color. In some skins there is a distinctly darker ventral stripe, 

 and occasionally the sides are of a brighter yellowish fulvous. In 

 some the top of the head is darker, in others lighter, than the restof 

 the dorsum; but in all the muzzle, sides, and under surface of the 

 head and neck are pale, so that the skin exhibits a triangular dark 

 patch above, corresponding to the crown of the head. 



Young of the year (from four skins taken in midwinter). — These are 

 strikingly paler than adults at the same season. They present a cen- 

 tral area of reddish brown and two broad, lateral bands of nearly 

 uniform brownish gray, faintly washed with fulvous. The ventral 

 surface is appreciably darkest in the median line. The sides of the 

 head are washed with fulvous. The rump and base of tail are 

 pale chestnut-fulvous, with less of the vinaceous tint than in adults. 



Three immature skins, presumably in their second and third years, 



