NATURAL SCIENCES OF PHILADELPHIA. 179 



Bas, 18G3, p. 33. [China.] Ssvinhoe, Ibis, 1863, p. 431. [China 

 Seas.] 

 Diomedea brachyurajuv. Cassin, Illust. B. Cal. & Tex., 1853, p. 291. Lawrence, 

 Baird's B. N. Amer., 1858, p. 822. 



Habitat. North Pacific. Coasts of Asia and America. 



Description* Bill about a third longer than the head, slightly surpassing the 

 tarsus, equal to the middle toe without its claw : comparatively stouter, and 

 basally wider, than that of any other species (except gibbosa?). The culmen 

 is perfectly straight to the middle of the bill; and has thence only a just 

 appreciable concavity to the unguis ; which latter is weak and small, scarcely 

 rises above the level of the culmen proper, and is only moderately decurved 

 and acute. The culminicorn is moderately wide, and subcnrinated beyond the 

 nostrils ; posterior to them it is flatter and wider, spreading down so far on 

 either side as to overlap the upper edge of the latericorn. Its comparative 

 width is greater than in any other species. Although the basal outline i3 

 essentially rounded, as in brachyura, there is yet a slight angle formed on the 

 median line, readily perceptible, which is not the case in brachyura. The 

 great comparative width of the bill is produced chiefly by the turgid and pro- 

 tuberant latericorns, which give it an air of great thickness and solidity. Tne 

 lateral sulcus is nearly straight from nostrils to unguis, and thence is only 

 slightly decurved. The commissure is almost straight to the unguis. The 

 outline of the inferior mandibular rami is quite straight to the inferior unguis. 

 the point of which is somewhat elongated and decurved. The interramicorn 

 is small and short, though quite convex in outline. The feathers on the side of 

 the lower mandible extend further than on the upper ; their outline has a gentle 

 convexity. The nostrils are of moderate size ; very short ; rather obliquely 

 placed, presenting upwards and forwards ; and the emargination of the cul- 

 minicorn, to allow of their protrusion, is very deep. 



The tail is of moderate length, contained about three times in the wing from 

 the carpal joint ; is nearly square, the feathers having but a slight graduation, 

 and all being broad to their very tips. (The tail of brachyura is contained 

 about 31 times in the wing.) 



The tarsus is less than the middle toe without its claw, about equal to the 

 inner without its claw ; slender, moderatelv compressed. The outer toe is 

 longer than the middle ; the tips of the claws fall together. The tip of the 

 inner claw about reaches the base of the middle one. 



The plumage is dark chocolate brown ; lighter and rather tending to plum- 

 beous gray on the under parts generally. Some of the dorsal feathers, and 

 most of the wing-coverts, have light grayish brown edges, as if faded ; and a 

 few feathers on the elbow are whitish except terminally. The region all around 

 the bill is hoary white for a limited space ; and then shades rapidly into the 

 prevailing color of the head. A streak over arid behind the eye and a spot 

 just in front of it are nearly pure black. The primary quills are black, with a 

 plumbeous cast on their inner vanes; their shafts bright yellow to near the 

 tips. The tail is brownish black; paler below; the shafts dull whitish except 

 apically. The long upper tail coverts which reach within one and a half 

 inches of the end of the tail, are lighter brown than the rest of the upper parts, 

 having sometimes a slight rufous tint. The feet and webs are black. The 

 bill in the dry state is dark brown, almost black on the nail; its basal por- 

 tions with a hoary glaucescence, its median portions tinged with reddish 

 brown. 



Chord of culmen 4-00, its curve 4-60, from feathers on side of upper mandi- 

 ble to its tip 3-50; ditto lower mandible 3-20; height of bill at base 1-50; 

 greatest width 1-25. Tarsus 3-70 ; middle toe and claw 4-50, outer do. 4-50, 

 inner do. 4-00. Wing 19 to 20. Tail about 6-50. 



The preceding paragraphs are descriptive of a most excellent species of Al- 



* Taken from several typical examples from the coast of California in Mus. Smiths. 



1866.] 



