RUM IN ANTI A-CAVICORNIA—OVIS MONTANA. 
677 
rise gently from the head, and curve a little backward and outward. They measure six or 
seven inches along the curve. 
The divergence of the axes of the horns of the bighorn at the base is at an angle of about 
67 degrees. 
Fig. 31. Left horn from in front. 
Fig. 32. Base of the horn. 
Size, 5.61 inches to the inch. 
I have already referred to the figure, by MiddendorfF, of a supposed horn of 0. montana, 
from the Sea of Okotsk. This differs appreciably from any I have seen, in being quadrilateral 
rather than triangular, thicker behind than before, and with a groove or furrow in the external 
plane. There is an abrupt bend upwards of the tip of the horn, which I have never observed 
in American specimens. In these, the exterior surface of the horn is only gently twisted, 
the basal half remaining in almost a true plane. The principal part of the twist is at about 
the middle of the horn, or at the base of the terminal third ; after which, there is again 
very little twist to the end. To bring back the outer surface of the horn to one plane, would 
only require the point to describe an arc of about six inches. In the Upper Missouri horns, the 
curve of the upper outline of the horn, viewed perpendicular to its plane, forms an apparently 
nearly true segment of a circle, (about three-fourths). In the California horns, this curve is 
more cycloidal. 
I have never had an opportunity of examining the Siberian argali, (Ovis argali , of Pallas,) 
supposed to be very similar to our species, and by some authors quoted as identical, nor have 
I found anywhere any satisfactory comparison of the two. Judging, however, from the very 
minute description of the argali, in Pallas’ Naturgeschichte merkwurdiger Tldere, Samml. 
xi, 1779, p. 1, tab. i, ii, it would appear to be rather smaller than the big horn, weighing but 
310 pounds (to 350); the total length, 5 feet 10 inches. The greatest apparent difference is in 
