NATURAL SCIENCES OF PHILADELPHIA. 25 



upright spine ; that of the lower eye-lid much as in other species of the 

 genus. 



Form otherwise as in F. arctica and glacialis. Larger than the former, about 

 the size of the latter. 



Crown of the head deep grayish black; the patch of this color triangular in 

 shape, narrowing anteriorly to a point at the base of the culmen. Sides of the 

 head white ; the furrow in the plumage behind the eye, and the sides of the 

 lower jaw tinged with dark ash. A narrow distinct line of white along the 

 edge of the fore-arm. Entire upper parts very glossy blue-black ; a duller, 

 more fuliginous shade of black encircling the neck before, and running for- 

 wards on the throat and chin quite to the bill. Other under parts pure white, 

 except a few elongated blackish feathers on the sides and flanks. Under sur- 

 face of wings dark pearly ash. Legs and feet orange red, the webs tinged 

 with Vermillion. Claws brownish black. Palpebral appendages apparently 

 ashy black. Bill yellow, tinged with red, the terminal portion blackish. Ric- 

 tal callosities brilliant yellow orange. 



Length 14-50; extent 2450; wing 7-25 ; tail 2-'75 ; tarsus 1-10; middle toe 

 and claw 2-00 ; outer do. 1-90 ; under do. L35 ; bill : chord of culmen 2-00, 

 its curve 2-25 ; rictus from basal rim to tip 1-20; gonys 1-75 ; depth of bill at 

 base 1-80 ; its greatest width -60; length of nasal slit -40; length of superior 

 palpebral appendage -35. 



This interesting species may be recognized at a glance by the prominent 

 horn over the eye, and the extension of the black collar on the throat to the 

 bill. The bill also differs from that of either of the other species in its short- 

 ness, compared with its great depth at the base, and the nearly smooth sides, 

 which are not distinctly divided by a ridge or groove into two compartments. 

 The bill is also comparatively thinner than that of the other species, and dif- 

 ferently colored. 



Prof. Naumann first described this species from Kamtschatka in his valu- 

 able memoir on the genus in the Isis, as above cited. It has been occasionally 

 confounded with glacialis Leach, which is quite a different bird. It is a North 

 Pacific and Arctic species, not recorded from the Atlantic. Excellent speci- 

 mens are contained in the Philadelphia Academy and Smithsonian Institution; 

 one of those in the collection of the last named is probably the original of 

 Audubon's plate of "glacialis." 



LUNDA, Pallas. 



Alca, Pallas, Spic. Zool. v, 1769; in part; and of some older authors. 

 Lunda, Pallas, (ex Gesn.) Zoog. R.-A. 1811. Type Alca cirrhata, Pallas. 

 Mormon, Illiger, Prodrome, 1811 ; in part ; and of most authors. 

 Fraterciila, Stephens, Shaw's Gen. Zool. xiii, 1825; in part; not of BrissoH. 

 Gymnoblephariim, Brandt, Bull. Acad. Imper. St. Petersburg, ii, 1837, p. 349. 



Type Alca cirrhata, Pallas. 



With somewhat the general aspect of Fratercula. No horny appendages to 

 the eyelids. No furrow in the plumage behind the eyes. An extremely 

 elongated crest on each side of the head. Upper mandible with only an indi- 

 cation of a basal ridge along its sides ; the culmen divided into two parts, 

 whereof the basal is surmounted by a prominent widened ridge, ending ab- 

 ruptly ; sides of upper mandible with three well marked curved grooves, 

 widely separated, whose convexity points backwards. Under mandible with 

 its sides perfectly smooth, and its base very convex, not concave. Rictus very 

 sinuate ; gonys slightly curved. Feet, wings and tail as in Fratercula. 



The above diagnosis indicates only the principal features wherein this 

 genus — or subgenus, as might be contended with some reason — differs from 

 Fratercula. Except in the bill, eye-lids and crest, the genus is exactly Frater- 

 cula, but the differences in these points seem sufficient to warrant generic 

 separation. 



1868.] 



