In Central and Northern Asia there were at one time no fewer than eight recognised varieties of giant wild sheep, viz. _O. Poli_, _O. Karelini_, _O. Heinsi_, _O. nigrimontana_, _O. Ammon_, _O. Hodgsonii_, _O. Brookei_, _O. nivicola_.
Mr. W. T. Blanford, however, after inspecting a magnificent collection of heads, made by Hon. C. Ellis, which exhibit every gradation of curve between the two extreme types, declared in his paper to the Zoological Society in 1884 that he considered _O. Poli_ and _O. Karelini_ to be practically the same species, and the formidable list may be further reduced from a sportsman’s view by massing the varieties into three broad types, viz:
1. _O. Poli_ with its little known varieties, _O. Heinsi_, and _O. nigrimontana_; for though these appear to differ somewhat in size (_O. nigrimontana_ being a comparatively small animal), their horns are of the same wide-spreading type.
2. _O. Ammon_, _O. Hodgsonii_ and _O. Brookei_; the difference between the first two is very trifling, and _O. Brookei_ is considered by some authorities to be possibly a hybrid between _O. Hodgsonii_ and _O. Vignei_ (Shapoo).
3. _O. nivicola_, which more nearly resembles _O. montana_ (the Bighorn of the Rocky Mountains).
The first type is found, according to M. Severtzoff, only in Turkestan, from the Pamir through the Thian Shan range as far eastwards as Tengri Khan; its varieties being located as follows: _O. Heinsi_ in the Tockmack district west of Tengri Khan; _O. nigrimontana_ in Karatan, near Samarcand.
The second type is not found in Turkestan. Its range is the Altai from Tengri Khan as far eastward as the sea of Baikal, and then southwards by the sources of the Hoang-ho and Yang-se-kiang rivers down to Ladak and the southern frontier of Thibet.
[Illustration: No. 1, extreme type, Ovis Poli]
[Illustration: No. 3, extreme type, Ovis Karelini]
In colour all these sheep are much the same; generally a rather rich greyish brown fading to greyish white towards the tail and belly, with, in the ram, a greyish white ruff on the neck. This is the chief distinguishing mark of a ram _Ovis Ammon_ at a distance, the ewe having a brown neck; in fact, the ram looks as if his thoughtful spouse had insisted on his wearing a white comforter for fear of catching cold. The horns of the ram, large as they are, are of such a pale colour as to be hardly distinguishable in certain lights at long distances. The _Ovis Poli_ appears to have little or no ruff, but has a dark line down the back, which the _Ovis Ammon_ has not, and has also a more clearly defined white anal disc.