MAMMALS OF THE MEXICAN BOUNDARY. 



241 



the color of the head as those above described, these being the only 

 bighorns I have examined in wliich the end of the muzzle and the 

 throat were not white. 



Skull and teeth. — The type is under-grown. Its posterior molars 

 were just coming up to their place, and there were but five lateral 

 teeth in each jaw (fig. 36). These teeth are large and intermediate 

 in measurements between comparable immature female topotype of 



Fig. 36.— Ovis canadensis gaillardi. Skull of type. (Cat. No. 59906, U. S. N. M.) 



Ovis canadensis nelsoni and O. c. mexicanns. The rostrum and 

 nasals are shorter, and the size smaller than in nelsoni or mexicanus. 

 The only adult skull (Cat. Xo. 59907, U.S.N.M.), a topotype, is 

 imperfect from weathering. It ditfers from all others in the pe- 

 culiar shape of the horns, which are strongly incurved (fig. 37), and 

 in the great distance (50 mm.) between them. The horn of the type 

 is shown in fig. 38. The molars are smaller than in nelsoni or mexi- 



FiG. 37.— Ovis canadensis gaillardi. Skull of adult male. (Cat. No. 59907, IT. S.N. M.) a. Lat- 

 eral VIEW; b, dorsal view. 



canus, but much larger than those of canadensis ; the tAvo posterior 

 molars, taken together, measuring 45 mm. in length; the greatest 

 breadth of the middle molar 16.3 mm. 



External measurements of type (immature female). — Total length, 



1,200 mm.; tail vertebra?, 120; ear from crown, 120; ear from notch, 



115 ; distance between eyes, 122 ; diameter of eye, 23 ; from tip of nose 



to eye, 167 ; to center of pupil, 184 ; to ear, 220 ; to tip of ear, 365 ; to 



30639— No. 56—07 m 16 



