MAMMALS. 



283 



Mr. C. L. McKay. They comprise a skin of au adult male and one of au adult female aud the 

 horus and scalp of a second female. In the following table the proportions of Mr. Nelson's speci- 

 mens are compared with those of a specimen of the normal variety from Montana : 



Mr. McKay's s])ecimeDS, from the Chigmit Mountains, present the following proportions. 

 13652 and 13653 are flat skins : 



Nos. 



If any conclusion is warranted by these few data, it is, perhaps, that the Alaskan sheep is con- 

 siderably smaller than its southern relative, aud that it carries to the extreme the variations in the 

 shape of the horn (extension and decrease in diameter at the base), observable in northern exam- 

 ples of the normal variety, 0. canadensis (typicus). 



It would be interesting to know the southern limit reached by Ball's sheep." 



List of specimen X. 



Biographical notes. — The discovery of this fine animal is one of the most valuable results of my 

 ■work in the north. It is limited to the higher mountain ranges of the Territory, except in the 

 extreme northern portion, within the Arctic Circle, where it ranges down nearly to the sea-level. 

 Following the main range of the Eocky Mouutaius it is found in the southeastern part of the 

 Territory and north along these mountains to the point where the chain swings to the west, and 

 along its western extension, known as the Alaskan range, it is numerous nearly to the head of 

 Bristol Bay. In this portion of the mountains Dall's Sheep is found upon the Pacific slojje as well 

 as on the northern side. I could not learn of its occurrence on tlie peninsula of Aliaska, although 

 some individuals mav be found there. 



* Sec a letter bv Lieutenant Alleu ou the Rnmiii 



: of the Cojiper Eiver Region in Science, vol. vii, p. 



