ALCIN^. MERGULUS. ALCA. 215 
282. Mergulus Alle. Little Botche. 
In winter, the upper part of the head, a portion of the 
cheeks, the hind part and sides of the neck, and all the upper 
parts of the body, black ; the tips of the secondary quills, and 
| the margins of some of the scapulars, Avhite, as are the 
throat, fore-neck, breast, and abdomen ; the uppermost fea- 
thers of the sides, with their inner webs, black, the lower 
wing-coverts greyish-brown. In summer the colours similar, 
I but the throat and fore-neck brownish-black, like the head. 
Mnlp Q 1 111 11 o __8 9 1 Jt 
maie, p, i, ij. 
This species occurs in summer in very high latitudes, and 
in winter retires southwards, along the shores of both conti- 
nents. Its food consists of small Crustacea and fishes, which 
, it procures by diving, its habits being similar to those of the 
Guillemots and Auks. It is of rare occurrence in Britain. 
I have seen two individuals on the Bass Bock, and have been 
credibly informed that it breeds in considerable numbers at 
St Abb’s Head. In the winter season, it has several times 
been obtained in England. 
Little Auk. Little Guillemot. Sea-Dove. 
Alca Alle, Linn. Sys. Nat. i. 211.— Alca Alle, Lath. Ind* 
Ornith. ii. 795. — Uria Alle, Temm. Man. d’Ornith. ii. 928. 
—Mergulus Alle, Little Botche, MacGillivray, Brit. Birds, 
ii. v. 
GENUS CXLII. ALCA. AUK. 
The Auks are very similar to the Guillemots, from which, 
however, they are distinguished by the form of the bill, 
which is as long as the head, stout, very high, much com- 
pressed, and obliquely furrowed on the sides ; the upper 
mandible with the dorsal line decurved, the ridge extremely 
narrow, the sides nearly flat, the nasal groove very large 
and feathered, the edges sharp and in fleeted, the tip de- 
curved, narrow, and obtuse ; the lower mandible with the 
angle very narrow, and having a horny triangular appen- 
dage, the sides toward the end erect and flat, the dorsal line 
ascending and concave, the tip decurved ; mouth of mode- 
rate width ; palate flattened with five prominent lines an- 
teriorly ; tongue slender, trigonal, tapering, pointed ; oeso- 
phagus wide, in its lower part, and the proventriculus enor- 
mously dilated ; stomach small, elliptical, with the muscular 
coat rather thin, the tendons round, the epithelium thin. 
