Family	HORNED-BILLED GUILLEMOT. [Rhinoceros Auklet.]
Genus	URIA OCCIDENTALIS, Bonap. [Cerorhinca monocerata.]

This species is from the north-west coast of America, the figure was taken from a specimen lent to me for that purpose by the Prince of MUSIGNANO.

CERORHYNCHA OCCIDENTALIS, Bonap. Syn., P. 428.
WESTERN CERORHYNCHA, Nutt. Man., vol. ii. p. 538.
HORNED-BILLED GUILLEMOT, Ceratorhyncha occidentalis, Aud. Orn. Biog.,vol. v. p. 104.

Adult, 15 1/2, wing, 6 10/12.

North-west coast of America.

Bill shorter than the head, stout, straightish, broad at the base, the mouth measuring seven-eighths of an inch across, compressed toward the end; upper mandible with an oblong compressed knob on the ridge between the nostrils, beyond which the dorsal line is declinate and decurved toward the end, the sides sloping, the edges sharp, the tip narrow, obtuse, with a distinct notch immediately behind it; the gap-line slightly arched; lower mandible with the angle long and rather wide, the dorsal outline ascending and straight, the sides sloping outwards and flattened, the edges thin and direct, the tip acute. Nostrils linear, near the margin, pervious.

Body full and compact; neck short and thick; head large, ovato-oblong. Feet short, stout, placed far behind; tibia bare for a short space; tarsus very short, anteriorly scutellate, laterally reticulate; hind toe wanting; anterior toes scutellate, of moderate length, connected by emarginate webs, the inner toe much shorter than the outer, which is nearly as long as the middle. Claws rather small, slightly arched, compressed, rather acute.

Plumage dense, blended, rather glossy on the upper parts. Wings of moderate length, narrow, pointed; primaries tapering, the first longest, the rest rapidly graduated, secondaries rounded. Tail very short, even, of sixteen elastic feathers.

Bill orange-yellow; feet greyish-yellow. The general colour of the upper parts is black, as are the cheeks, the upper part of the fore neck and its sides; the lower parts white. Two decurved white bands on the sides of the head, one commencing over the eye, the other at the angle of the mouth, both being formed by elongated, linear, acuminate feathers. The shafts of the wing-feathers are reddish-brown above, white beneath.

Length to end of tail 15 1/2 inches, to end of claws 16 3/4; bill along the ridge 1 (5 1/2)/12, not including the outline of the knob, which is (4 1/2)/12 high, along the edge of lower mandible 1 10/12, breadth of upper mandible below the knob, (2 1/2)/8; wing from flexure 6 10/12; tarsus 1 (4 1/2)/12; inner toe 1 2/12, its claw 5/12; middle toe 1 1/2, its claw (5 1/2)/12; outer toe 1 5/12, its claw 5/12.