OVIS. 



137 



With regard to the distinctions between this species and the 

 other two of which there are examples in the Museum, the skull 

 differs from that of 0. poli but slightly, in O. hodgsoni there is a 

 very marked depression between the bases of the horn cones on 

 the forehead, while the space is quite flat in O. poli ; the great differ- 

 ence, however, is in the horns, while those of O. hodgsoni are 

 enormously massive at the base, they are never very long, i e., 

 they describe a little more than half a circle when viewed laterally, 

 while those of O. poli are considerably more slender at their 

 bases and the older ones describe a complete circle when viewed 

 laterally ; the proportions of the circumference at the base to the 

 total length measured along the frontal surface is as follows in 

 typical specimens : — O. hodgsoni, circumference of the horn at the 

 base, 17 inches; length of horn, 30 inches; O. poli, circumference, 

 15 inches; length, 50 inches. 



The horns of Ovis canadensis are of much the same external 

 form as those of O. hodgsoni as far as the curves are concerned, 

 they differ, however, markedly in being almost smooth and not 

 marked by the very conspicuous transverse furrows and ridges 

 present in the horns of both O. poli and O. hodgsoni ; the 

 nuchal edge in O. canadensis is very much rounded, much more 

 so than in the largest and oldest horns of O. poli, and the nuchal 

 surface is also markedly rounded instead of being flat as in O. 

 hodgsoni and O. poli ; in the skull the premaxillae and nasal 

 bones are much shorter than in those of the Asiatic Argalis and 

 they are distinctly articulated the one with the other, which is not 

 the case with the Asiatic forms. 



Altogether the Asiatic and American forms seem very distinct. 



a. Skull and^ G. T. Lushington ? A. S. B. 



horns. 



b. Skull and^ No history. 



horns. 



c. Skull and^ No history. 



horns. 



d. Skeleton $ G. T. Lushington, A. S. B. 



^.Stuffed $ G.T. Lushington, A. S. B. 



/. Head and^ No history. 



horns. 

 ^. Skin and? W. T. Blanford, 1870. 



skull. 

 A. Skull $ Thibet? No history, A. B. S. 



y. Skeleton $ No history, A. B. S. 



k. Head andj Capt. Michell. 



horns. 

 /. Skin, skull ^ btw. Ladak and Kukchu N. Elias, 1879. 



and horns. 15,000 ft. 



Ovis canadensis. 



Ovis canadensis, Shaw Nat. Misc., xv, pi. 610 (1804) ; Biddulph P. Z. S., 

 1885, p. 678. 



