1899.] NATURAL SCIENCES OF PHILADELPHIA. 277 



are most conspicuous. From ears to base of tail the black and 

 white predominate, producing a clear gray, blackening irregularly 

 along median line and very faintly tinged with buff. On the sides 

 the buff becomes more conspicuous and slightly darker, and on the 

 sides of the belly both white and black practically disappear. 

 Chin, upper side of muzzle and posterior half of upper lip dusky. 

 Cheeks, sides of muzzle, throat and median line to base of tail 

 buffy white. Inner sides of thighs and area between them white. 

 Bases of ears, area behind ears, on sides of neck and across chest 

 ochraceous buff. Distal half of ears duller than base. Inner sur- 

 face buffy white. Outer sides of front legs and posterior surface of 

 hind legs ochraceous buff'. Anterior surface of hind leg and dorsal 

 surface of pes buffy white. Soles and palms ochraceous buff". 

 Tail gray with a black dorsal stripe and tip and ill-defined ventral 

 buffy area. 



Skull. — The skull is exactly similar to that of Urocyon frater- 

 cuhis. It therefore needs no comparison with that of any of the 

 members of the cinereoargeiiteus group. 



Measurements of skull of type:^ greatest length, 102; basal 

 length, 94.4; basilar length, 92; palatal length (median), 47; 

 nasals (median), 30; zygomatic breadth, 53; interorbital breadth, 

 20.4; breadth across postorbital processes, 30.4; greatest breadth 

 of brain case, 40.6; mastoid breadth, 36.4; greatest depth of 

 brain case, 33.6; space between audital bullae, 5.6; upper tooth- 

 row (exclusive of incisors), 41; mandible, 74; mandibular tooth- 

 row (exclusive of incisors), 46. 



Teeth. — The teeth of Urocyon parvldens are uniformly much 

 smaller than in U. fmterculus, but the differences are most con- 

 spicuous in the first molar and the second, third and fourth pre- 

 molars. The greatest diameter of the crown of the first molar in 

 three specimens of U. parvidens is respectively, 8.8, 8.8 and 8.6. 

 In the type of U. fraterculus it is 10.6. The greatest diameter of 

 the crown of the carnassial in three skulls of U. imrvidens is 9.2, 



^ The skull of the type of U. fraterculus measures : greatest length, 101 ; 

 basal length, 93 ; basilar length, 91 ; palatal length (median), 48 ; nasals 

 (median), 31 ; zygomatic brt^adth, 53.6; interorbital breadth, 19.6 ; breadth 

 across postorbital processe.s, 30 ; greatest breadth of brain case, 40 ; mastoid 

 breadth, 37.4 ; greatest depth of braincase, 31 ; space between audital bullae, 

 6; upper toothrow (exclusive of incisors), 44 ; mandible, 74 ; mandibular 

 tooth row (exclusive of incisors), 48.6. 



