888 



U. S. p. R. R. EXP. AND SURVEYS— ZOOLOGY — GENERAL REPORT. 



COLTMBUS TORQUATUS, Briinnich. 

 The Great Northern Diver; The Loon. 



Colijmhus torquatus, Brunn. Orn. Bor. ]764, 134. 



Colymbus glacialis, Linn. Syst. Nat. I, 1766, 221.— Forster, Phil. Trans. LXU, 1772, 383.— Wils. Am. Orn. IX, 

 1824, 84, pi. Ixxiv.— BoNAP. Syn. 1828, No. 368 —Rich. & Sw. F. B. Am. II, 1831, 474.— 

 NuTT. Man. II, 1834, 513.— Aud. Orn. Biog. IV, 1838, 43, pi. 306.— Ib. Birds, Am. VII, 

 1844, 282 ; pi. ccccLx-xvi. 



Colymbus immer, Linn. Syst. Nat. I, 1766, 222. (Young of year.) 



Sp. Ch. — Bill compressed, strong and tapering, outline of upper mandible nearly straight, very slightly curved ; the lower 

 mandible has a groove underneath, running from the junction of the crura towards the point; the tail consists of twenty 

 feathers . 



Jidult. — The head and neck are dark bluisli green, the upper part and sides of the head glossed with purple ; tliere is a small 

 transverse mark on the throat, composed of while feathers of a quill hke form, distinct from each other and placed longitudinally 

 on each side of t!ie neck ; lower down are larger patches of white, of the same peculiar form, and running in the same direction ; 

 these almost meet behind, and in front are about one inch apart ; the eflect of these pure white feathers, relieved by the dark 

 color of the neck, is very beautiful ; the upper plumage and wing coverts are deep glossy black, beautifully marked with pure 

 white spots placed in regular transverse rows, slightly curving downwards ; these spots, on the upper part of the back, are small 

 and nearly round, but as they descend lower on the back increase in size and become quadrangular in form, being largest on the 

 scapularies ; on the lower part of the back, upper tail coverts and sides (which are black,) the spots are small and round ; the 

 sides of the neck, near the shoulder, are beautifully lineated with black and white ; the primaries, secondaries and tail brownish 

 black ; the under surface glossy white, with a narrow band of dusky feathers crossing the lower part of the abdomen, and 

 marked with small white spots ; lower tail coverts blackish brown, tipped with white ; bill black ; iris deep bright red ; tarsi and 

 feet greyish blue externally, tinged on the inside with pale yellowish red ; webs brownish black ; claws back. 



Length, 31 inches ; wing, 14 ; tarsus, 3| ; bill, 3 ; height at base, 1. 



Young.^—Xhe plumage above is greyish black, the feathers of the back margined with greyish white, the under plumage pure 

 white, bill yellowish with the ridge of the upper mandible dusky. 



Ilab, — Very generally distributed ; it is abundant on the Atlantic coast, in the lakes of the interior and the fur countries 

 Specimens are in the collection from iho Pacific coast and from New Mexico. 



There are two specimens in adult plumage^ and a head of a young individual from the 

 Pacific coast; two ot the young from New Mexico. Individuals vary considerably in size, some 

 measuring 36 inches in length. 



Locality. 



When col- Whence obtained 

 lected. 



Carlisle, Pa .May 18,1844 S. F. Baird . 



.do. 



Apr 26,1845 do . 



Coast of New Jersey . 



Fort Thorn, N. M .... 

 8ho:il water bay 



Steilatoom, W. T... 

 do 



.' Cab. of Geo. N. 



Lawrence. 

 .1 Dr. T. 0. Henry. 

 .' Gov. Stevens.,.. 



Ilr. Sackley . 

 do 



Orig'l 



No. 



575 



Collected by — 



Dr. Cooper . 

 Dr. Potts ... 



Length. ! Stretch 

 of ffinss. 



.^1.50 

 31.00 



30.00 

 31.00 



54.00 

 56.00 



Wing. 



14.00 

 14. 5U 



14.50 

 14.00 



Color of iris blood rod, 

 feet blue 



COLTMBUS AECTICUS, Linnaeus. 



The Black-throated Diver. 



Odymltui arcticui, Lins. Syst. Nat. I, 1766, 2-21.— Bo.vap. Syn. 1828, No. :iG!).— Rich, aud Sw. F. IS. A. II, 1831, 

 475.— NuTT. Man. H, 1831, 517.— Aud. Orn. Biog. IV, 1838, 345.— lit. Birds Am. VII, J844, 

 395; pi. pccclxxvii. — Gray Genera, III, f'.'.i); pi. clxxi. 



