A pair of Dall sheep.
Dall sheep definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a wild sheep (Ovis dalli) with white hair and long spiral horns, living in the mountains of NW North America
also Dall's sheep
Dall sheep definition by American Heritage Dictionary
or Dall's sheepnoun
A stocky wild sheep (Ovis dalli) of the mountainous regions of northwest North America, ranging from white to nearly black and having curved yellowish horns.
Origin: After William Healey Dall (1845-1927), American naturalist.