534 NORTH AMERICAN BIRDS. 



and black bands, more numerous spots of white on the head, etc. The inner 

 webs of inner secondaries are banded with white, not uniform black. The 

 maxillary black stripe is rather larger than the rictal white one, not smaller. 

 The size is decidedly smaller. Females almost always have the top of head 

 spotted with white instead of uniform black, which is the rule in arcticus. 



It is probable that the difference in the amount of white on the upper 

 parts of this species is to some extent due to age and season, the winter 

 specimens and the young showing it to the greatest degree. Still, however, 

 there is a decided geographical relationship, as already indicated. 



This race of P. tridadylus can be easily distinguished from the European 

 form of Northern and Alpine Europe by the tail-feathers ; of these, the outer 

 three are white (the rest black) as far as exposed, without any bands ; the 

 tip of the third being white only at the end. The supra-ocular white stripe 

 is very narrow and scarcely appreciable ; the crissum white and unhanded. 

 The back is banded transversely in one variety, striped longitudinally in the 

 other. In P. tridadylus the outer two feathers on each side are white, 

 banded with black ; the outer with the bands regular and equal from base ; 

 the second black, except one or two terminal bands. The crissum is well 

 banded with black ; the back striped longitudinally with white ; the supra- 

 ocular white stripe almost as broad as the infra-ocular. P. crisoleucus, of 

 Siberia, is similar to the last, but differs in white crissum, and from both 

 species in the almost entire absence of dark bands on the sides, showing the 

 Arctic maximum of white. 



We follow Sundevall in using the specific name americanus, Brehm, for this 

 species, as being the first legitimately belonging to it. P. Mrsutus of Vieil- 

 lot, usually adopted, is based on a European bird, and agrees with it, though 

 referred by the author to the American. The name of undulatus, Vieillot, 

 selected by Cabanis, is based on Buffon's figure (PI. enl. 553) of a bird said 

 to be from Cayenne, with four toes ; the whole top of the head red from base 

 of bill to end of occiput, with the edges of the dorsal feathers narrowly 

 white, and with tlie three lateral tail-feathers regularly banded with black, 

 tipped with red ; the fourth, banded white and black on outer web, tipped 

 with black. None of those features belong to the bird of Arctic America, 

 and the markings answer, if to either, better to the European. 



Habits. This rare and interesting species, so far as has been ascertained, 

 is nowhere a common or well-known bird. It is probably exclusively of 

 Arctic residence, and only occasionally or very rarely is found so far south as 

 Massachusetts. In the winter of 1836 I found a specimen exposed for sale 

 in the Boston market, which was sent in alcohol to Mr. Audubon. Two 

 specimens have been taken in Lynn, by Mr. Welch, in 1868. They occur, 

 also, in Southern Wisconsin in the winter, where Mr. Kumlien has several 

 times, in successive winters, obtained single individuals. 



Sir John Eichardson states that this bird is to be met with in all the 

 forests of spruce and fir lying between Lake Superior and the Arctic Sea, and 



