NATURAL SCIENCES OP PHILADELPHIA. 227 



Urinator, Cuvier, 1799-1800, fide G. R. Gray. 

 Eudytes, Illiger, 1811 ; (Eudites, Kaup, 1829.) 



1. Colymbus tokquatus Briinnich. 



C. torquatus, Briiun. 1764; G. glacialis, Linn. 1766, auctor. pleriq ; ad. 

 C. immer, Briinn. 1764; Linn. 1766 ; Gmel. 1788 ; Lath. 1790 ; juv., 

 Cepphus torquatus, Pall. 1811, ad. ; C. imber, Pall. 1811, juv. ; Eudytes 

 glacialis, Illiger, 1811 ; Eudites glac. Kaup. 1829. 



2. Colymbus Adamsii G. R. Gray. 



Colymbus Adamsii, Gray, Proc. Zool. Soc. Lond. 1859, 167. 



Sp. Ch. Form and general appearance that of C. torquatus, but larger, with 

 the bill disproportionately larger, and differently shaped. 



Bill very large and strong, about equal in length to the head, longer than 

 the tarsus, greatly compressed, the tip very acute, not decurved. Culmen 

 very slightly, scarcely appreciably, convex. Commissure perfectly straight. 

 Gonys straight, or very nearly so, to the angle, which is prominent, well 

 defined ; and straight, or even a little concave, to the tip. Feathers of fore- 

 head extending beyond the middle of the nostrils. Groove along the sym- 

 physis of the lower jaw extending but little beyond the angle. 



Adult. Bill light yellowish, growing dusky at the base. Head and neck 

 all round deep steel blue, with purplish and violet reflections, and glossed on 

 the back of the neck with deep green. Gular patch of white streaks very 

 small, less than in torquatus, but the individual streaks larger, as are also 

 those on the side of the neck. Upper parts generally as in torquatus, but the 

 spots considerably larger, and on the scapulars and tertials rectangular, instead 

 of nearly square, being much longer than broad. Otherwise like torquatus. 



Plumage of the young unknown. 



Bill above 3-70 ; along gape 5-25 ; height of nostril anteriorly 1-10 ; width, 

 50; tarsus 3-50; outer toe 4-65 inches. "Irides light reddish-brown, legs 

 and feet olivaceous." 



Habitat. Russian America (Gray). Arctic America (Ross, Kennicott). 



Table of Distinctive Characters. 



C. torquatus. Bill 2-75 inches, not longer than the tarsus ; moderately 

 compressed ; black : the tip only sometimes yellowish. Culmen very convex. 

 Commissure decurved. Gonys regularly convex throughout its whole length, 

 the angle scarcely appreciable ; the groove along symphysis extending nearly 

 to tip. Feathers of the forehead falling short of the middle of the nostrils. 

 Head and neck mostly deep glossy green. White spots of back moderate, 

 scarcely longer than broad. 



C. Adamsii. Bill 3*75 ; longer than the tarsus ; exceedingly compressed ; 

 light yellow, except at base. Culmen very slightly convex. Commissure 

 straight. Gonys straight, or nearly so, to the angle, straight, or even a little 

 concave to the tip, the angle prominent, well defined. Groove along sym- 

 physis very short. Feathers of forehead extending beyond the middle of the 

 nostrils. Head and neck mostly deep steel blue. White spots of back large, 

 much longer than broad. 



There cannot be, I think, the slightest doubt of the specific distinction of 

 the present species and the C. torquatus. The difference in the size, shape, 

 and color of the bill alone would separate the two, were there no other char- 

 acters involved. It is every way a much larger bird. The species is, so far 

 as we are aware, now for the first time presented in an American work. The 

 original description, by Gray (as above), is very brief, but the distinctive 

 characters of the species are so concisely stated that we have no difficulty in 

 identifying the large series before us with the description. The Loon men- 

 tioned by Audubon, as having "the point of the bill recurved, and of a fine 

 yellow tint," was very possibly an individual of this species. The type of 



1862.] 



