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variety of the Mountain Sheep known as 07'>s Canadensis Dal/i, Nelson. 

 The specimen seen was shot on a steep rocky slope near the summit of 

 the range, and in rolling down, the skin and horns were injured so 

 severely as to render them useless as specimens. This variety of the 

 Mountain Sheep differs from the typj of the species in its smaller size, 

 in its uniform white colour, and in the slenderer build of the horns, but 

 all these characters appear to he variable. The first information in 

 regard to this animal is given in a short article by Mr E. W. Nelson 

 in the proceedings of the U. S. National Museum, Vol. VII., p. 12, 

 18S4. (See also Report u[)on Natural History collections made in 

 Alaska between the years 1877 and 1881 by Edward W. Nelson, p. 

 282, issued in connection with the Signal Service U. S Army, 1887. 

 Mr. Nelson in this article describes the colour as a dingy white and 

 states that the hairs are tipped with a speck of rusty colour. Lieut. 

 H. T. Allen, U.S.A., on the other hand in a letter in " Science," Vol. 

 VII., p. 57, 1886, stales that the sheep seen by him on the head waters 

 of Copper River, Alaska, were by no means dingy, but were, in fact 

 nearly as white as their surroundings of snow. The latter statement 

 agrees with my own observation, as the animal shot by my Indians 

 was almost pure white. Another variation in colour was reported to 

 me by some miners on the Yukon, who described some sheep shot by 

 them on the upper part of this river as having a brown patch on both 

 sides behind the fore shoulders, and referred to them as the " Saddle- 

 backed Sheep." The latter probably mark a stage in a progressive 

 change in coloration from the nearly uniform dull-brown of the normal 

 species to the pure white of the northern variety. 



The diminution in size of the northern sheep i.s even more 

 remarkable than the change in coloration. Those shot in the southern 

 part of the Canadian Rockies range in weight up to three hundred 

 pounds, while the sheep brought into Fort Macpherson from the 

 mountains west of Red River, according to Mr. Hodgson the officer in 

 charge of .hat post, seldom exceed a hundred pounds in weight Some 

 of the specimens seen by Lieut. Allen, U.S.A., on the high snowy 

 mountains at the head of Copper River, Alaska, are described by him 

 as being as large as the ordinary Big-horn, while others met with only a 



