URINATORIDiE — THE LOONS — URINATOR. 453 



Young : Similar to that of U. immer, but usually much smaller, the angle of the mandible less 

 prominent. 



Total length, about 29.00 inches; extent 39.50 ; wing, 12.15-13.20 (average, 12.55); culmen, 

 2.50-2.85 (2.60); depth of bill through base, .75-.80 (.78); tarsus, 2.90-3.30 (3.11); outer toe, 

 3.45-3.95 (3.76). (Five adults.) 



The only North American examples of this species in the National Museum collection are 

 from Alaska ; several localities in that country being represented, as the Prybilof Islands and 

 St. Michael's. 



Summer adult. 



The young of this species, particularly full-grown specimens, are sometimes difficult to distin- 

 guish from immature specimens of U. immer; but the measurements will in most cases determine 

 the species, U. arcticus being decidedly smaller ; the two comparing about as follows : — 



U. arcticus, juv. 12.00 2.53 



U. immer, juv. 13.00 or more 3.20 



This species appears to be common to the Northern and Arctic Regions of the 

 globe, though more so in some parts of the high northern regions than in others. It 

 is very rare, and not even positively known to occur, in the United States. It is more 

 common in the regions of Hudson's Bay, and thence westward. On the Pacific it is 

 replaced by the pacificus, similar, but of smaller size and weaker bill. 



Mr. Murray procured specimens on Hudson's Bay, and Hearne (" Journey,'' p. 

 430) refers to the presence of this Diver in the same region, and speaks of it as being 

 about the same size as U. immer, and more beautiful than that bird. It is extremely 

 watchful, diving at the flash of a gun, and being of course very rarely killed, except 

 when on the wing. Its flesh is quite as dark and fishy as that of the common Loon, 

 but it is always eaten by the Indians. The skin of this bird is very thick and strong, 

 and is frequently dressed with the feathers on, and made into caps for the Indian 

 men. This Loon is also spoken of by Dr. Richardson as being common on the shores 

 of Hudson's Bay, but very rarely seen in the interior. He mentions the fact that the 

 skins both of the common Loon and of this species are tough and impervious to wet, 

 and says that they are used both by the Indians and the Eskimos as materials for 

 dress. 



According to Mr. Kumlien, this species breeds, but is not common in Kingw'ah 

 Fiord, where it was first seen June 24. A few individuals were seen in autumn 



