732 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Genus CEPPHUS Pallas. 



CeppJius Pallas, Spic. Zool., v, 1769, 33 (Type, C. lacteolus Pallas=.4?ro gnjlle 



Linnseus, albino.) 

 Grylle Leach, in Ross's Voy. Disc. Baffin's Bay, App., 1819, p. li. (Type, G. xcap- 



ularis Leach =J.Zca grylle Linnseus.) 

 Pseuduriao- Sharpe MS. Coues, Osprey, iii, Zvlay (pub. June 10), 1899, 144. 

 (Type, "Black guillemots with 14 xecir\CQB= Cepphus columba Pallas, etc.). — 

 Sharpe, Hand-list, i [July 12], 1899, xiv, 131. 



Medium-sized Alcidse (wing 149-181 mm.) with bill narrow, culmen 

 rather abruptly decurved terminally, gonys much less than half as 

 long as unfeathered portion of mandibular rami, and nasal fossae 

 unfeathered for nearly the anterior half (the feathered portion form- 

 ing a distinct angle or loral antia), with the slit-like nostrils in lower 

 edge. 



Bill (measured from rictus) about as long as head, narrow, decidedly 

 deeper than wide at base of culmen; exposed culmen about as long 

 as tarsus, faintly concave sub-basally (the mesorhinium slightly as- 

 cending basally, more or less flattened on top), thence nearly straight 

 to near tip, where rather abruptly decurved; gonj^s nearh^ straight, 

 ascending terminally, much shorter than unfeathered portion of man- 

 dibular rami, decidedly less than half as long as culmen; nostril lon- 

 gitudinal, slit-like, in extreme low^er edge of the nasal fossa, the latter 

 well-defined and rounded anteriorly, the basal half (more or less) 

 feathered, the latero-frontal or loral antia forming a distinct angle, 

 the apex of which is slightly posterior to anterior end of nostril, its 

 lower edge overhanging and concealing basal portion of nostril; malar 

 antia forming a distinct angle, its apex slightly ])osterior to posterior 

 end of nostril; mental antia on same vertical line with latero-frontal 

 antia. Wing moderate, the longest primary (outermost) exceeding 

 distal secondaries by less than half the length of wing. Tailless than 

 one-third (slightly more than three-sevenths) as long as wing, rounded 

 the 12-14 rectrices rounded at tip. Tarsus about as long as exposed 

 culmen, much compressed, the outer side reticulate, the inner side 

 (except on planta tarsi) with much larger, more or less quadrate and 

 transverse, scales, arranged in two or more rows; middle toe, without 

 claw, slightly longer than tarsus; outer toe (without claw) as long 

 as, or very slightly shorter than, middle toe, the inner toe as long as 

 first two phalanges of middle toe. 



Plumage and coloration. — Plumage of head dense, rather short (es- 

 pecially anteriorly) but less velvet}^ than in Uria and other Alcinse. 

 Adiilts in summer plain sooty black or dark sooty brown, with or 

 without white on wing-coverts; feet red (in life) ; winter plumage and 

 young mostly white. 



Range. — Circumpolar regions and southward to northeastern 

 United States, California, and Japan. (Five, possibly six, species.) 



a ipivSris, false; + Uria. (Richmond.) 



