28 



ITOKTH AMEEICAl^ FAUNA. 



[No. 40. 



Characters. — In general like Cynomys leucurus but smaller and 

 with color of upperparts in summer and winter decidedly reddish or 

 rich cinnamon, less buffy or grayish; tail with terminal half white, 

 as in leucurus. Skull as in leucurus j but smaller, with greater in- 

 terorbital breadth. 



Color. — Adult in late summer: Entire upperparts of head and body 

 cinnamon or dark buffy cinnamon, with very little admixture of buff 

 or blackish hairs; the individual hairs blackish at bases, then narrowly 

 pale buff, broadly cinnamon, and tipped with dark brown. Spot of 

 black a,bove eye very sharply marked; cheek patch of brown distinct; 

 sides of nose pale buff; eye ring, ears, and limbs cinnamon; feet dark 

 buff; lips and chin whitish; underparts buffy or cinnamon. Tail for 

 half its length above concolor with rump; below cinnamon; terminal 

 half all around white, without markings. Adult in early winter pelage: 

 In general like summer coat but with dense underfur which is black 

 at base, then light buff; upperparts rich cinnamon, the long hairs with 

 broad bands of black and buff; sides of body yellowish buff, distinctly 

 marked from color of back, and streaked by the bands of black on 

 the longer overlying hairs. 



Molt. — Owing to lack of material collected at certain seasons, the 

 molt of C. parvidens is not well known. A single skin collected in 

 the Sevier National Forest, May 19, is still entirely in the old winter 

 coat. Specimens collected in late August and early September are 

 mostly in rather worn summer coat, with little indication of molt. 

 The tails are in freshly renewed pelage. Some specimens, taken the 

 first week in September, are well advanced in renewal of winter pelage, 

 with full underfur and long, fresh coat. Evidently the transition from 

 summer to winter coat is gradual and obscure, without a distinct 

 molt, much as in the animals of the northern part of the ranges of 

 C. ludovicianus and C. leucurus. A series of skins collected in the 

 Sevier National Forest, October 27 to November 3, are in full win- 

 ter coat. 



SJcull and teetJi. — Skull much like that of C leucurus, but smaller 

 and with greater interorbital breadth; postorbital processes less ab- 

 ruptly projecting. The teeth are not noticeably smaller. 



Measurements. — ^Averages of 8 adult males from Utah : Total length, 

 338 (305-360); tail vertebrse, 43 (30-57); hind foot, 59 (55-61). 

 Slcull: Condylobasal length, 55.9 (53-57.9) ; zygomatic breadth, 42.2 

 (38.3-44.5);*^mastoid breadth, 28.6 (26.7-29.8); length of nasals, 21.8 

 (20.5-22.4); length of mandible, 42.3 (40.3-43.7); maxillary tooth 

 row, alveoli, 15 (14.8-15.4). For detailed measurements of specimens 

 see page 35. 



Type specimen. — No. 28738, American Museum of Natural History, 

 New York. Adult not sexed, but probably a male; skin and skull 



