BIRDS OF NORTH AND MIDDLE AMERICA. 711 
the distal half of mandible with as many, or more, similar, but more 
vertical, grooves; nostril entirely concealed beneath lower edge 
of the dense velvety feathering of lores, which anteriorily forms a 
nearly straight but faintly concave oblique line across base of max- 
illa. Wings relatively very small, unfitted for flight. Tail short, 
graduated, composed of 14 rectrices. 
Plumage and coloration.—Plumage of head short, very dense 
and velvety, especially on anterior portion. Upper parts black, 
the secondaries tipped with white; under parts immaculate white; 
in summer, head and neck dark sooty brown, except a large oval 
area of white covering greater part of space between bill and eye. 
Range.—Formerly inhabiting coasts and islands of the northern 
Atlantic Ocean south of the Arctic Circle, but extinct since 1844. 
(Monotypic,). 
PINGUINUS IMPENNIS (Linnzus). 
GREAT AUK. 
Adults in summer (sexes alike).2—Chin, throat, foreneck, and sides 
of head and neck uniform velvety dark snuff brown or soft blackish 
brown, passing gradually into brownish black on pileum and hind- 
neck; a large oval patch of white covering greater part of space 
between bill and eye; upper parts Uniform black, the secondaries 
tipped with white; under parts, including chest, immaculate white, 
this ending anteriorly in an angle on median portion of upper chest 
or lower foreneck; bill black, its grooves whitish; iris dark brown; 
legs and feet black; wing, about 146; tail, about 76; exposed culmen, 
80-89; greatest depth of bill, about 38.1; tarsus, 42.16; middle toe 
with claw, 82.5.° 
Extinct since 1844; formerly occurring on coasts and islands of the 
northern Atlantic Ocean from southern Greenland, Iceland, and 
Norway southward to Massachusetts (Ipswich; Nahant; islands in 
Boston Harbor) and northern portion of British Islands (11 Brit- 
ish records), 
[Alca] impennis Linnaus, Syst. Nat., ed. 10, i, 1758, 130 (Norwegian seas); ed. 12, 
i, 1766, 210.—Gurun, Syst. Nat., i, pt. ii, 1789, 550.—_Latuam, Index Orn., 
ii, 1790, 791.—Covgs, Key N. Am. Birds, 1872, 339. 
4T have not seen any description of the winter plumage or young of this species, 
and no specimens of either are available for examination. Judging from analogy 
in the case of related forms, however, they would probably differ from the summer 
plumage, as described above, in having the dark brown of the throat and foreneck 
(probably portions of the sides of the head also) replaced by white. 
b No sexed specimens are avilable for measurement. The total length of speci- 
mens examined varies from 736 to 762 mm., and Audubon gives the expanse of wings 
as 27,25 inches=641.34 mm. 
