“D. alba, rostro nigro, carina mandibulæ superioris basique inferioris flava, capite grisco, cenia, macula supra oculos caudaque obscuris, dorso, alis maculaque inter rostrum et oculos nigris. Irides fuscæ; nucha et uropygium alba; pedes pallide ochroleuci, anterius cum membranâ digitos connectente obscuri.”

Feet.In.
Length of the body from the tip of the bill to extremity of the tail2
Length of the bill04
Depth of the base of the bill0
Length of the tail0
Length of the tail, exserted from feathers of the urupigium0
Length of the thigh06
Length of the tarsus03
Length of the middle phalanges04⅜
Breadth of wings expanded64
Breadth between the wings from the first scapular joint05
Length of the first joint09
Length of the second joint0
Length of the third joint0
Length of the fourth joint, or pen-feathers13
Length from the inner angle of the eye to the base of the beak01
Breadth of the foot when expanded0

The plumage was clean, delicate, and very handsome, particularly about the head. From this bird I procured a small parasitical animal, probably a Ricinus, which was found rather numerous about its feathers, it is prettily marked on each side, with a silvery appearance on the back, when viewed through a microscope.

The upper surface of the wings, scapulars, and back in this bird, was a brownish black; the urupigium, white; the head, chin, and neck, of a delicate grey, or blue grey. The back is shaded off towards the neck, which becomes of a soft and beautiful leaden colour, of more light and delicate tints as it proceeds around the front part of the neck, extending towards the breast; eyelids black: the upper surface of the tail was of a light black; shaded with white in a very delicate and beautiful manner. At first, this appearance was supposed only to be the result of the different lights in which the bird was occasionally placed; but subsequent observations confirmed its being the marked colour. On examining one of the tail-feathers plucked from the bird, it was found delicately tinted; the shaft diminishing gradually as it proceeded from the quill to the extremity, until it terminated in a very fine filament, projecting one-eighth of an inch from the plume; this was observed in the whole of the upper and large tail-feathers. The plume as it came off on each side from the base, terminated in a beautiful downy appearance; tail-feathers underneath of a lighter colour—vent (crissum) white, which gives a light delicate appearance to the edge of the feather.

The breast and abdomen are of a snow-white; under surface of the wings, upper line along the wing-bones, and a little below, brownish-black; middle white, (excepting a few brown feathers near the axilla,) forming a continuous broad white line the whole length of the under surface of the wings; lower feathers base white, tips black, under surface of the pen-feathers black; shafts white.

At the inferior part of the external angle of the eye, around the margin of the lid, a narrow white mark extends for the length of seven-eighths of an inch. A diffused black-mark was situated over, and extended to the inner angle of the eye, terminating near the base of the bill in lighter shades of the same colour, forming an agreeable contrast with the delicate leaden hue extending over the head and neck.

Bill blackish; upper surface horny, (shaded with light black at some parts,) extending, of a similar appearance, to the hooked process of the upper mandible. At the lower part of the inferior mandible, this horny appearance also extends to within an inch of the tip. Irides brown; the first pen-feather the longest; feet and legs marbled, the web marbled blue, more at the anterior edges, and between the second and third toes; claws of the toes turned outwards, (to the right.)

There is a very minute tubercle at the posterior, and lower part of the tarsus, which is considered by some as a rudiment of thumb, and I suppose to be that alluded to by Lesson, when he says of this genus, “pouce sans ongles.”

The fœces of this specimen were of a reddish purple colour, as if occasioned by his swallowing some Aplysiæ; but the skeleton of a Loligo was solely found in his stomach, the interior of which, as well as the whole length of the intestinal canal, was seen on dissection to be tinged of a similar colour; but no remains of Aplysiæ were to be found: could the colour, then, have been produced by the Loligo? The second stomach contained one perfect and one imperfect beak of a sepia, both of small size. The gizzard or second stomach is small in proportion to the size of the bird.

The specimen was a female; the cluster of ovaries of a yellowish colour, and situated just above the superior lobes of the kidneys, were distinctly seen.