890 



U. S. p. E. E, EXP. AND SOEVEYS — ZOOLOGY — GENEKAL KEPOET 



an examination of specimens of C. arcticus, in the Museum of the Phil. Acad., I found a fully 

 adult individual ; also one approaching maturity. These were precisely alike as regarded the 

 form of their bills ; there was also a specimen of a young bird labelled " C. arcticus," but, 

 having no locality marked upon it, it came with the Rivoli collection, and was originally from 

 that of the Duchess de Berri ; the bill was weak and slender compared with the two other spe- 

 cimens, and the whole appearance of the bird quite different. I could not, therefore, reconcile 

 them as being the same ; the young specimen in the Phil. Acad, was exactly like the species 

 now described, and may have come from the Pacific. 



Pvichardson Fauna Bor. Am., vol. II, p. 475, describes the young of "C arcticus," as "closely 

 resembling those of ' C. glacialis,' but may be distinguished by their inferior size, a slight 

 curvature of the upper mandible, and the want of a groove on the under one, which is not 

 thickened in the middle." 



The above described specimens bear very little resemblance to " C. glacialis," which strengthens 

 my opinion in thinking them distinct from C. arcticus. The true position of the Pacific species 

 can only be surely settled by obtaining it in adult plumage. 



COLYMBUS SEPTENTRIONALIS, Linn. 



The Red-throated Diver. 



Columbus septenirionalis, Linn S. N. I, 1766, 220.— Bonap. Syn. 1828, 370.»-Eich. and Sw. F. B. A. II, 1831, 476.— 

 Nltt. Man. II, 1834, 519.— Aud. Orn. Biog. Ill, 183?, 2U: V, 1839, 625.— Is Birds Am. 

 VII, 1844, 299; pi. cccclxxviii. 



Colymlus lumme, Brlnn. Oru. Bor. 1764, 132. 



Colymhus stellatus, BrOnn. Orn. Bor. 1764, 130. 



Colymhus striaius, Gm. I, 1788, 556 (young.) 



Colymhus borealis, Lath. Ind. Orn. II, 1790, 802 (young.) 



gp. Ch. Adull. Front, sides of the head, upper part of the throat, and sides of the neck, clear bluish gray; upper part of the 



head of the same color, intermixed wiih blackish spots ; the hind neck streaked longitudinally with white on a greenish black 

 ground, the white feathers being raistd above the others. On the fore pait of the neck is a large longiDudiual patch of deep 

 reddish brown. Upper plumage brownish black, slightly tinged with green, and on the upper part of the back aud lower part 

 and sides of the neck streaked and mottled with white. Wings and tail brownish black ; under plumage pure white, with a band 

 across the hind part of the abdomen, and the lower tail coverts brownish gray ; bill bluish black ; iris bright red ; tarsi and feet 

 brownish black externally, on the inside pale flesh color; claws yellowish at the base, dusky at the end. 



Length, 27 inches; wing, 11^; tail, 2^ ; bill, 2^; tarsus, 2|. 



Youny. Upper part of the head and hind neck dull gray, streaked with grayish white ; back and wings blackish gray, pro- 

 fusely marked with oval shaped white spots, there being two on each feather, smallest on the upper part of the back and largest 

 on the tertiaries; quill feathers and tail blackish brown, the latter edged with white ; sides of the neck white, speckled minutely 

 with gray; under plumage silky white, crossed on the lower part of the abdomen by a dusky baud ; bill bluish gray, dusky on 

 the ridge and flesh colored at the base. 



Hah. — During the winter as far south as Maryland ; inhabits as far north as the Arctic seas ; found also on the Pacific coast. 



Two specimens are in the collection from the western side of the continent, and present no 

 marked differences from those of the Atlantic coast. No. 9923 is in the anomalous dress of an 



