2. 
3. 
ALCIDA — ALCINZ: GUILLEMOTS. 815 
or sooty, little varied with white; under parts white, marbled, rayed and waved with dusky; 
incipient mirror spotty. Nestlings are covered with sooty brownish-black @own ; bill and feet 
brownish-black. Perfectly white and entirely black birds are rarely seen. The mirror on the 
upper surface of the wings is composed of the terminal half (more or less) of the greater coverts, 
the rest dark ; of the several next rows excepting their dark bases, the white of these coverts 
normally overlying and concealing the dark basal portions of the greater coverts, so that the 
oval mirror is usually unbroken; the anterior border of the mirror is the line through the union 
of white tips with dark bases of the row of lesser coverts about 4 an inch from the fore-arm 
edge of the wing. When, as not seldom happens, the row of greatest coverts are dark beyond 
the extent of the next row, this dark being thus 
uncovered, shows as a wedge partly splitting the 
mirror, as normally occurs in U. columba. Or, 
©) the greater row of coverts may be entirely dark, 
when the mirror is unbroken, as before, but much 
smaller ; or, again, the middle row of coverts may 
be tipped with dark, making a break across the 
mirror, but in a different method from that first 
described. Finally, the mirror may be only in- 
dicated by isolated white feathers, or wholly want- 
ing. Length, average, 13.00; extent, average, 
22.50; wing 5.50-6.25; tail about 2.00; tarsus 1.25; middle toe and claw 1.75; bill 1.30; 
gape 1.75; gonys 0.65; depth of bill at base 0.45, width 0.35. Eur. and N. Am. coasts and 
islands of the N. Atlantic, very abundant; rare or casual in the N. Pacific, where replaced by 
the succeeding species; occurring in the Arctic Ocean, but apparently mostly replaced by U. 
mandti ; in N. A. occurring in Hudson’s Bay, and 8. in winter to the Middle States. Gregari- 
ous; flying in close flocks low over the water; nesting scattering in rifts of rock near the 
water; eggs 2-3, sea-green, greenish-white or white, spotted and blotched most irregularly 
with blackish-brown, and with purplish shell-markings; size 2.25 to 2.50 X 1.50 to 1.60; 
shape nearly elliptical, not pyriform like those of Guillemots; laid in June, July. 
U. colum’/ba. (Lat. columba, a pigeon. Fig. 553.) Pianon Gui~itemor. Bill stouter than 
that of grylle, and more obtuse. No white on under surface of the wing. White mirror of 
upper surface nearly split in two by an oblique dark line, caused by the extension of the dark 
bases of the greater coverts, in increasing 
amount from within outward, till the outer- 
most are scarcely tipped with white ; con- 
sequently there is a dark wedge between ») 
the white ends of the greater and middle 
rows of coverts. Plumage and its changes 
otherwise as in the foregoing; general 
habits and nesting the same. Asiatic and 
Am. coasts and islands of the N. Pacific ; 
Fig. 553. — Pigeon Guillemot, nat. size. 
breeds as far south as California. 
U. carbo. (Lat. carbo, a coal; ie. Fic. 554. — Sooty Guillemot, nat. size. 
black. Fig. 554.) Soory GuILLemMoT. Sprcractep Gui~iemot. Like the last; larger. 
especially the bill. No white on either surface of wings. A pair of white spectacles on the 
eyes, and whitish about base of bill. General plumage and its changes as in others of the 
genus; bill and feet the same. Length 14.00-15.00; wing 7.75; tail 2.50; tarsus 7.35; 
middle toe and claw 2.10; bill 1.55-1.70 along culmen, along gape 2.20, from feathers on 
side of lower mandible 1.50; depth at base 0.50; width 0.388. N. Pacific, in higher latitudes; 
British Columbia to Japan. An interesting species, still rare in collections. 
