34 NORTH AMERICAN FAUNA (iO, ITSH AND WILULIIE SERVICE 



ders in some individuals) overlaid with blaciv, the general tone due 

 mainly to hlack-tipped liairs with a h<i;hter subterminal zone, thechirk 

 brownish undcifur showing through to some extent; sides of body 

 somewhat lighter, the black tips of hairs shorter or black-tipped hairs 

 less numerous than on median dorsal area; top of head mixed black 

 and white or grayish, giving a coarsely grizzled effect ; black mask 

 enclosing eyes, but more or less discontinuous on middle of face where 

 a blackish median line is more or less distinctly isolated by lighter 

 lateral lines; upper surface of muzzle usually brownish; facial mask 

 bordered above by rather broad and conspicuous wiiitish lines extend- 

 ing posteriorly across cheeks to sides of neck; sides of muzzle, lips, 

 and chin white; under parts, in general, thinly overlaid with long 

 grayish or buffy overhairs only partially concealing the dense under- 

 fur, which varies from near wood brown to chestnut bown; throat 

 crossed by a brownish or blackish area, separated from facial mask 

 laterally by narrow wdiitish or buffy lines extending posteriorly from 

 muzzle; ears densely clothed inside and out with short, whitish or 

 buffy hairs, merging with the general pelage on external basal portion; 

 black postauricular patches usually large and conspicuous; forearms 

 and thighs similar to under parts, but hind legs more or less distinctly 

 blackish near heels; fore and hind feet, including toes, whitish, the 

 soles black and naked; tail above w4th five to seven narrow black 

 rings and a black tip, alternating with broader grayish or ochraceous 

 buffy rings, the black rings less sharply defined and sometimes inter- 

 rupted below. Young (in first pelage) : Color markings as in adults, 

 but top of head, nape, and postauricular spots nearh^ pure brow^nish 

 black, in contrast to the lighter, generally buffy, tone of dorsum, over 

 which the black-tipped hairs beginning to appear are still incon- 

 spicuous. 



Cranial characters. — Skull rather small, with moderatelv high, nar- 

 row frontal region; brain case depressed near fronto-parietal suture; 

 postorbital processes of frontals small or obsolescent; postorbital 

 processes of jugal w^ell developed. Very similar to that of P. I. hirtus, 

 but much smaller, less massive; sides of frontals behind orbits usually 

 more deeply indented or constricted, the result being that sides of 

 brain case are more rounded or bulging, less tapering antei-iorly; 

 dentition relatively the same. Not very unlike that of P. I. solufus, 

 but longer and relatively narrower; frontal region usually narrower; 

 palatal shelf longer, extending farther posteriorly beyond posterior 

 molars; dentition usually somewhat lighter, the large molariform teeth 

 rather narrow, but maxillary tooth row longer as a rule, owdng to wider 

 spacing of premolars. Similar in general form to that of P. I. litoreiis, 

 but smaller, and dentition relatively much lighter, the difference most 

 marked in the molariform teeth. Compared with that of P. I. Dariua, 



