LEPOEIB\<E—LEPUS AMERICANUS VAR. BAIRDI. 311 



from pale yellowish-gray to yellowish-brown, varied with black. The hairs 

 have a very long black tip, with a narrow subterminal bar of yellowish- 

 brown, of varying intensity; thence to the base black. The effect of the 

 long black tips is to give a much greater prevalence of black over the other 

 tints than is seen in the other forms of americanus, imparting a general sooty 

 tint to the whole upper surface. In some specimens, the black is quite the 

 prevailing tint, especially over the rump, which region, in some specimens, 

 is wholly black, varied with white by the white under fur showing through 

 the, surface color. The feet are wholly white, and there are generally a 

 few white hairs on the back — traces, doubtless, of the winter pelage. The 

 anterior part of the body above and the head are more or less rufous, this 

 tint being most developed on the upper surface of the head. The white 

 under-fur (varying in different specimens from white to grayish-white) always 

 shows through the surfacecolor more or less, and is conspicuous on the slightest 

 disarrangement of the pelage. In one specimen only (No. 11099, from Lewis 

 Lake, "Wyoming Territory) is there a very decided trace of the yellowish 

 zone that terminates the under-fur in the other forms of Lepus americanus. 



Typical examples in summer pelage of this peculiarly interesting form 

 give the impression of its being thoroughly distinct from any other form of 

 americanus; but comparison of a series of specimens from the original locality 

 of L. baiidi with others from the Red River district reveals a decided tendency 

 to intergradation between these forms. The most prominent distinctive fea- 

 tures of var. bairdi in summer pelage are its pure white under-fur, the long 

 black tips of the hairs, and the white feet, and in winter the tendency of 

 the pelage to become pure white to the base. Some of the summer speci- 

 mens frcm the Red River district and from Fort Rae (northern shore of 

 Great Slave Lake) also have white feet, and the pale yellowish-gray of the 

 back is also strongly varied with black, and the under-fur is simply dusky, 

 without the fulvous "termination. Again, occasional specimens of bairdi 

 have the fulvous apical zone of the under-fur slightly developed. Var. 

 bairdi, in its blackish-gray dorsal surface and white under-fur, bears a strong 

 resemblance to summer specimens of L. timidus var. arcticus, from the Arctic 

 coast; but the great disparity in size and the differences in the skulls forbid 

 the supposition of any very close affinity between them. 



The few measurements obtainable from the considerable series ot skins 

 before me (mostly in a very bad state) are presented in the following tabic 

 The length varies from 15.50 to 18.00 inches, but on one or two of the 



