MOUNTAIN SHEEP NOTES 255 



edge that his description of that form is accredited by 

 Mr. Sheldon as the original cause of his extensive explora- 

 tions for sheep in the wild Northwest. 



The Black Mountain Sheep is the darkest in color, 

 or one may say the most nearly black, of all American 

 wild sheep. North of the Stickine River it is not so black 

 as it is farther south, where the blackness of its head, 

 neck and body is very pronounced. In the majority of 

 cases, its horns are so characteristic that any studious per- 

 son should be able to recognize the species by them alone. 

 The front angle of the horn is very sharp, and near the 

 base it actually overhangs the face of the horn. This 

 feature is constant. In about nine cases out of every ten, 

 the horns of the Black Sheep are distinguished by their 

 widely-spreading spiral, and the great distance between 

 the tips. Occasionally, however, a head develops horns 

 with a more narrow spiral, like those of the typical White 

 Sheep ; but all such are exceptional. 



The White Sheep has an immense range, covering 

 half of Alaska, and practically the whole of Yukon Terri- 

 tory. It is all over pure white, save when stained by con- 

 tact with wet earth or dulled by age. Occasionally an 

 individual is found which has a few dark hairs in its 

 tail, and others thinly scattered on its hind quarters. Of 

 the original species, Ovis dalli, two subspecies have been 

 described; but neither are separately discernible without 

 a close examination of their skulls. In section, the horns 

 of the White Sheep are very much like those of the Black 

 Sheep, but those of northwestern Alaska show the flat 

 spiral, and have the tips closer together. The exceptions 



