676 U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
The hair of this species is very coarse and spongy in the summer, coarser than in the deer, 
rather finer than that of the antelope, which it resembles in crimping, sponginess, brittleness, 
and coarse thread-like appearance. In summer there appears to be no under coat, but in 
winter there is probably more or less of it, as in an autumn specimen there is a considerable 
amount of a rather fine wool, of short staple, but probably never in sufficient amount to be of 
any value. 
According to Mr. Audubon, a large bighorn will weigh about 350 pounds, perhaps more. 
It is larger than a Virginia deer, much more so than the domestic sheep. 
The horns are of immense size, and provided with transverse ridges or constrictions. They 
arise above the eyes, the middle of their root being about opposite the posterior border of the 
orbit. The inner bases of the horns are almost in contact, separated only by the space of half 
aninch. They rise for a short distance, then curve gently backwards, diverging throughout 
their course until they have described rather more than a semi-circle. Their section is rather 
triangular throughout, becoming much compressed towards the apex, which is twisted outward. 
Their curve is such that, with the base of the skull in a horizontal plane, the truncated tip 
comes back to about the vertical plane of the occiput, its upper edge about one and a half inches 
below the horizontal plane. In one old animal the horns are 19 inches apart at the tip; they 
measure 154 inches in circumference at the base, and 28 inches in length around the curve. 
They weigh 184 pounds with the perfectly clean skull, lacking the end of the nose and the 
lower jaw. Inthe specimen brought by Captain Stansbury from the Rocky Mountains, how- 
ever, the horns are 18 inches in circumference at the base; the horn along the convexity 
measures 363 inches, and the tips are 18 inches apart. 
The section of these horns at the base is sub-triangular, the outer and upper sides of the 
triangle nearly straight, the inner convex. Thus there are two planes to the outline of the 
horn, and one curved surface. The exterior face of the horn is quite plane, the application of a 
straight edge showing it to be only slightly convex. In no one of many horns have I seen 
anything like the very decided valley (or notch in cross section) exhibited in Middendorff’s 
figure of his supposed O. montana, from the Sea of Okotsk. The upper face of the horn is 
likewise only gently convex, the two planes meeting at less thana rightangle. The remaining 
face of the horn, or that constituting the internal and posterior surface, is convex. Generally 
the transverse diameter of the horn at its base is as long, a little longer, or but little shorter 
than the antero-posterior. 
In a bighorn from California, on the 35th parallel, fig. 30, the horns are less massive, measur- 
ing only thirteen inches in circumference at the base, and two feet along the external upper ridge, 
along the convexity of the curve. The plane character of the exterior and superior faces, is 
very decided ; as is also their triangular section, the base of the triangle (anterior) being less 
than the straight side. The horns are very much compressed towards the end, and terminate 
in a rounded tip. These tips are 19} inches apart, and distant eleven inches in a straight line 
from the anterior base of the horn; the ordinate of the arc, of which the straight line is the 
chord, measures 8} inches from the convexity of the horn. ‘The orbits are appreciably larger. 
In the female the horns are much smaller, and more like those of a male goat not fully 
grown, They are compressed laterally, the sides curved, and more flattened to the tip. They 
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