724 COLYMBUS SEPTENTKIONALIS, feED-THROATED DIVER. 



The foiitbers look as dry as if the bird had never beeu under water ; the 

 fish is swallowed head tirst, with a curious jerkiug Qiotiou, aud the bird 

 agaiu swims at ease, with the same graceiul curve of the neclv. 



COLYMBUS SEPTENTRICmALlS, Linn. 



Red-throated Diver. 



Cohjinhns f^cptcnfrinimlis, Lixx., Syst. Nat. i, 1766, 220 (adult). — Lath., Iiul. Oin. ii, 1790, 

 801.— Tkmm., Mail. 181.< 602.— Eoie, Isis, 1822, 561.-Steph., G. Z. xii. 18:4, 

 2:W.— Keys. & Bi.as., Wirb. Eur. 1840, 91.— Gi;ay, Gen. of IJ. iii, 6:51.- Sund., 

 Sveusk. Fogl. p]. 53.— Br., Syu. 1828, 421; List, 1838. 65.— Sw. & Ricii., F. B. 

 A. ii, 1831, 476.— NuTT., Mau. ii, 1834, 519.— Aud., Oni. Biog. iii, 1835, 20, pi. 

 202; Svu. 1839, 354; B. Aui. vii, 1844, 299, pi. 478.— GiH., B. L. L 1844, 380.— 

 Lawk.,' B. N. A. 1858, 690; Ami. Lye. N. Y. viii, 1866, 300 (New York).— Coues, 

 Pr. Phila. Acad. 1862, 228.— Newt., Ibis, 1865, 317 (Spitzbcrgen).— Coop. & 

 Suck., N. H. Wash. Ter. 1860, 279.— Dale & Bann., Tr. Chic. Acad, i, 1869. :',07 

 (Alaska).— FiNSCU, Abh. Nat. iii, 1872, 75 (Ala.ska).— Tt:km$., B. E. Pa. 1869, 

 39 (rather rare). — CouE.s, Key, 1872, 335; and of authors generally. 



Cepjylnis septcntrioiiaUa, Pall., Zoog. Rosso- As. ii, 1811, 342. 



Eiidytes sq){cntrioiialis, III., Prod. 1811, 282.— Naum., Vog. Dent, xii, 1844,^435, pi. 329. 



Colymhus Imnme, BiiiJNN., Orn. Bor. 1764, 39 (adult). 



Colymbus steUatus, Bluxx., Orn. Bor. 1764, No. 130 (young).- Gm., Syst. Nat. i, 1788, 

 £87.— Latil, lud. Orn. ii, 1790, 800.— Leach, Cat. 1816, 35. 



Citp2)]uis stcllatus, Pall., Zoog. R.-A. ii, 1811, — . 



Colymbus horcalis, BKtJxx., Orn. Bor. 1764, No. 131.— LATH.jKud. Oru. ii, 1790, 801. — 

 Bkehm, V. D. 1831, 979. 



Colymhus striatus, Gm., Syst. Nat. i, 1788, 586 (young).- Lath., lud. Orn. ii, 1790, 802. 



Colymhus rvfognlaris, Meyei:, Tasch. Deutsch. Vog. ii, 453. 



Colymhus microrhynchus, Breiim., Nauiu. v, 1855, 300. 



Hah.— The Northern hemisphere. 



Char. Bill usually slenderer than in the foregoing ; culm en slightly concave at the 

 nostrils, gently convex to tip, which is rather obtuse and a little decurved. Outline of 

 rami nearly straight; gonys slightly convex. Frontal antiiu scarcely extending beyond 

 base of nostrils. Tarsus relatively rather longer than in foregoing siiecies, about four- 

 fifths the middle toe. 



Adult. — Bill black, rather lighter at the tip. Crown and broad cervical stripe glossy 

 greenish-black, the latter thickly streaked with white, which streaks, ou the sides of 

 the brea.st, sjiread so as to nearly meet in front. Throat and sides of head clear bluish- 

 gray. A large, well-detined, triangular, chestnut-brown throat-patcii. Entire upper 

 parts aud sides under the wings deep biowuish-black, with greenish gloss, everywhere 

 profusely spotted with white, the spots small, oval. Primaries blackish, pal^" ou the 

 inner webs. Tail narrowly tipped with white. Under parts and lining of wings white, 

 the axillars with narrow, dusky shaft-streaks, aud the lower belly, with some of the 

 under tail-coverts, dusky. 



Young. — Bill mostly light bluish-white, with dusky ridge. Crown of head and neck 

 behind bluish-gray, the feathers of the former bordered with whitish. Entire upper 

 parts brownish- or grayish-black, everywhere profusely marked with small oval and 

 linear spots of while. Throat without red patch, its sides and those of the the he.ad 

 mottled with dusky. Other parts as in the adult. 



Dimensions. — Length, about 27; wing, 11 or less; bill alongculmen, 2; along gape, 3; 

 height at nostril, 0.50; width there, 0.35; tarsus, 2.75; outer toe, 3.50. 



Tills species varies greatly in general size, and in the size and shape of the bill. 

 Nevertheless, it may always be recognized bj' the peculiar profuse siiotting of the upper 

 parts, as well as, when adult, by the red throat-patch. The spots are smallest and mo.st 

 numerous ou the wing-coverts and upper back, where they gi'ad<i into the streaks of 

 the hind neck ; largest on the tertials, scapulars, aud sides under the wings, where they 

 are lather lines than spots, and are fewest, or almost wanting, on the middle of the 

 back. The marking results from a small spot or stripe near the end of each feather, 

 ou the edge of each web; there is occasionally a second pair nearer the ba.se of the 

 feather. The amount of spotting is very variable with individuals ; in the young the 

 spots are always larger aud more numerous than in the adults, aud usually leugtheued 

 into oblique lines, juoducing a regular diamoud-shaped reticulation. 



A specimen (No. 9923) collected by Mr. George Gibbs, on the Northwestern Bounds ry 

 Survey, is an albino — a state I have not observed in either of the other species. T.'ie 

 neck aud upper parts are pure white, irregularly mottled with jnitches of light reddish- 

 ash, of which color are the primaries, wing-coverts aud Hanks. The bill is slenderer 

 aud more recurved thau usual, the culmen being coucave throughout. The siiecimen 

 measured 24 by 44 in extent, the wiug 9.90. 



