16 NORTH AMERICAN BIRDS. 
Genus CEPPHUS Pattias. (Page 9, pl. IL., fig. 3.) 
Species. 
Common CHaracters.—Summer adults uniform black, with or without white 
on wings. Winter specimens white, varied above (sometimes below also) with black, 
the wings and tail as in summer. Young similar to winter adults, but white of 
wings varied with dusky, the quills marked at tips with white. Bill black; feet 
bright red in summer, pinkish in winter. Hgg varying from ovate to elongate- 
ovate, greenish white or buffy white, heavily spotted or otherwise conspicuously 
marked with dark brown and lavender-gray. 
a. A large white patch on outer surface of wing. 
o. Under wing-coverts pure white. 
cl. Greater wing-coverts white to the extreme base, sometimes a little 
dusky along the basal portion of the shafts. Adult in summer: Uni- 
form blackish, except a large roundish or oval patch of pure white 
on the wing, including the greater, middle, and posterior lesser 
coverts, these feathers all white to the base; axillars, under wing- 
coverts, and basal half, or more, of inner webs of quills, pure white. 
Winter plumage: Wings as in summer; rest of the plumage pure 
white, the upper parts varied with black. Young: Similar to winter 
plumage, but white wing-patch broken by blackish tips to all the 
feathers; secondaries and primary coverts marked with white at 
ends, and lower parts indistinctly barred with dusky. Downy young : 
Uniform sooty blackish, paler and more grayish below. Length 
about 12.50-13.50, wing 6.25-7.20, culmen 1.00-1.20, gonys .50, depth 
of bill at nostril 35-40. gg 2.38 X 1.36. Hab. Circumpolar sea- 
coasts, south in North America, in winter, to New Jersey and 
Norton Sound, Alaska. (Breeding south to Hudson’s Bay and coast 
of Labrador.) .........06 28. C. mandtii Licut. Mandt’s Guillemot. 
ce. Greater wing-coverts with at least their basal half black, this often 
showing as a narrow bar beyond tips of middle coverts; plumage 
otherwise as in C. mandtii, and measurements nearly the same, but 
bill larger and stouter; length 12.00-13.80, culmen 1.20-1.30, gonys 
-55-.60, depth of bill at nostril 40-45. Hogg 2.25 x 1.55. Hab. 
Coasts of northern Europe; also from southern Greenland along 
Labrador coast and south, in winter, to New Jersey ; breeding from 
Newfoundland and southern Labrador to vicinity of Eastport, 
Main€ (7) ..0cccesssaseaevereseees 27. C. grylle (Linn.). Black Guillemot. 
b%. Under wing-coverts smoky gray. 
Greater wing-coverts black basally, this increasing in extent toward 
edge of the wing, where occupying almost the whole extent of the 
outermost feather, thus producing a broad black “ wedge” between the 
two white areas; plumage otherwise as in C. grylle, with similar 
seasonal changes, etc.; length 13.00-14.00, wing 6.90-7.30, culmen 
