720 COLYMBUS TORQUATUS, GKEAT NORTHERN LOON. 



Co'lymhua immer, Lixx., Syst. Nat. i, 1766, 222.— Gm., Syst. Nat. i, 1788, 588.— Lath., Ind. 



Orn. ii, IT'JO, 800.— Leach, Cat. Ir^lB, 36. 

 Cohjml'is atrigulnris, JIbykr, Taschenb. Viig. Deutsohl. ii, 449. 

 Colymhus maximm et Memalis, Bkkhm, V. D. 971, 972. 



b. adamsii. 



Cohjmbus adamsii, Gkat, P. Z. S. 1S59, 167 (Russian America).— CouES, Pr. Pliila. Acad. 



1S32. 227; 1864, 21 (cranium).— Ellu>t, B. N. A. pi. 63.— Dall & Baxx., Tr. 



Chic. Acad, i, 1869, 308 (Alaska).— Finsch, Abh. Nat. iii, 1872 (Alaska). 

 Colynibus torquatun var. adamsii, CouES, Key, 1«72, 334. 

 Colymbus glacialis, var., Swinhoe. 



Bab. — The Northern hemisphere. Var. adamsii from Alaska and interior of Arctic 

 America ; also, Asia. " England." 



Var. TOEQTJATTJS : Common Loon. 



Adult. — Bill black, the tip and cutting edges sometimes yellowish. Feet black. Head 

 and neck deep glossy greenish-black, with lustrous purplish reflections on the front 

 and sides of the head. A patch of sharp white streaks on the throat, and another 

 larger triangular patch of the same on each side of the neck lower down, the two last 

 nearly or quite meeting behind, separate in front. Sides of breast striped with black 

 and white. Entire upper parts, wing-coverts, inner secondaries, and sides under the 

 wings, deep glossy bluish-green ; all except the sides thickly marked with white spots ; 

 those of the scapulars, tertials, and middle back, large, square, .and regular ; those of 

 other parts smaller, oval, smallest on rump, most numerous on wing-coverts. Upper 

 tail-coverts greenish-black, immjiculate. Wing-quills brownish-black, lighter on inner 

 webs. Under surface of wings, axillars, and under parts generally from the neck, pure 

 white ; the lower belly with a dusky band. 



Young. — Bill smaller than in the adult, bluish-white, with dusky ridge. Crown and 

 cervix dull brownish-black ; other njiper parts similar, but the fe.athers, especially of 

 the foreback, with light gray edgings. Primaries black, with brown inner webs. Tail 

 feathers with gray tips. Traces of lighter and darker lineation on sides of breast. 

 Sides of head mottled with ashy and whitish; chin, throat, neck in front, and whole 

 under ijarts, white. 



Dimensions. — Length 31 to 36 inches; wing, 12.50 to 14.2.5; bill, 2.75 to 3 along oul- 

 men ; gape, 4 to 4.25 ; height at nostrils, about 0.80 ; width there, about 0.40 ; tarsus, 

 3 to 3.50 ; middle toe and claw, 4.25 to 5. 



Bab. — The Northern hemisphere. In winter, gener.illy dispersed in the United States. 



The white throat-patch consists usually of five or six streaks; in this, as iu the lat- 

 eral neck-stripes, the individual feathers are broadly black, with sharp white edges 

 toward their ends. The texture of the feathers is peculiar — the outer surface is hol- 

 lowed, with raised edges of specially firm, smooth, polished character, so that these 

 patches may be felt as well as seen. The white spots on the back occur in a pair on 

 each feather near its end, their aggregation iu any region being therefore determined 

 by the size of the feathers themselves. 



Beginning binomial nomenclature at 1758, the name tnrquatus, Briinn. (1764), ante- 

 dates glacialis, Linn. (1766). No synonyms require discussion. 



Var. adajvisii : Yellow-hilled Loon. 



Ch. Larger than C. torquatus, with the bill rather larger and somewhat differently 

 shaped and colored. Bill about equaling head, longer than tarsus, ninch compressed, tip 

 very acute, not at all decurved, the culmeu being almost perfectly straight, as the com- 

 missure also is. Gonys straight or nearly so to the angle, which is very prominent. 

 Frontal antiiE reaching beyond middle of nostrils. Bill fine light yellowish horn-color, 

 only dusky at base. Head and neck deep steel-blue, with purplish and violet reflec- 

 tions, glossed only on the cervix with deep green. Throat-patch of white streaks 

 smaller than in torquatus, but the individual streaks larger, as are those of the neck- 

 patches. White spots of upper parts larger than in torquatus, rectangular instead of 

 sijuare on the scapulars and tertials, being somewhat longer than broad. Bill along 

 culmen, 3.50 to 3.75; along gape. 5 to 5.25 ; height at nostrils, 0.95 to 1.10 ; width, 0.40 to 

 0..50 ; tarsus, 3.50; outer toe, 4.65 to 5.10. General dimensions somewhat exceeding 

 those of torquatus, but not so much so as in the bill. 



A comparative table of characters is subjoined : 



lar. TOKQUATCS : Culmen, 2.75 to 3 ; gape, 4 to 4.25 ; height of bill at nostrils, aver- 

 age, uiider 1. Bill along culmen shorter than tarsus. Color of bill mostly black, its 



