636 U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
probably to the northwest coast ; to the north it reaches as far as Melville Island, or even still 
further. It is also found in Greenland, whence the skulls and horns in the Smithsonian col- 
lection were obtained. 
It is a question, admitting this to be a distinct species, whether it should bear the name of 
groenlandicus or arcticus. Following the strict law of priority, however, I have retained the 
former, although objectionable on account of its local character. 
