ALCIDiK — THE AUKS — CEl'l'UUS. 



489 



Genus CEPPHUS, Pallas. 



Uria, Bniss. Orn. VI. 1760, 70 (part), et Aucx. 



Cepphus, Pall. Spic. Zool. V. 1769, 33 (type, C. ladcolus. Pall., = C. grylle, albino). 



Gnjlle, Leach, in Ross's Vo}'. Disc. N. W. Pass. App. 1819, \^. li (type, G. scupularis, Leach, == 



Uria grylle, Puunn., + U. Maudti, Licirr.). — Brandt, Bull. Ac. St. Peteisb. IL 1837, 346 



(type, U. gryllcy Buunn.). 



Char. Size medium. Bill decidedly shorter tliaii head, al)out e(|ual in lenj^h to the tarsus, 

 moderately compressed ; upper and lower outlines straight and nearly parallel for about the ba.sal 

 half (or more), the terminal portion of the culmen gently decurved, the gonys (which is less tlian 

 half as long as the culmen) gently ascending, straight, or slightly convex ; nasal fossae only partly 

 feathered, occupied chielly by membrane, the nostrils narrow, slit-like, in the lower edge of the 



C. Mandtii, summer dress. 



fossa) ; no furrow in the plumage behind the eye. Color in summer uniform blackish, with or 

 without a white wing-patch. 



The characters given above are merely the more prominent ones distinguishing this genus from 

 its allies, more especially Uria, which by many authors has not been considered as distinct from 

 Cep2)hus. 



Five species are known, all but one of them being certainly North American ; they differ as 

 follows : — 



A. A large white patch on the outer surface of the wing. 

 a. Lining of wing pure white. 



1. C. Mandtii. Greater wing-coverts white to the extreme base, sometimes with a little dusky 

 along the basal portion of the shafts. U'ing, about (5.50 inches; culmen, 1.(XV-1.10; 

 gonys, .50 ; depth of bill through middle of nostril, .35 ; tarsus, about 1.30 ; midiUe tin, 

 with claw, 1.60-1.G5. Hub. Circumpolar Regions and Northern North Americii, south 

 in winter to New Jersey and Norton Sound, Alaska. 

 VOL. n. — G2 



