624 LARUS MAEINUS, BLACK- BACKED GULL. 



placed by a pearly gray-blue shade like that of the mantle. Yonng birds in all stages 

 are paler and grayer than the corresponding stages of ar(/en1atiis. Agreeing with JeAi- 

 copterus in respect of size, (jlauctscens may be immediately known by the pattern of the 

 j)rimaries; the pearly-bine color continning imdiminished in intensity to the tips of 

 the feathers, instead of fading gradually into white as in glaucns and Jeucopterus. 



I have never seen a specimen purpoi'ting to be " chalcoj^ ferns," which Mr. Lawrence 

 admitted in 1858. As described, it is "exactly like leucoptcrus, except on the primaries, 

 which are ashy-gray, with rounded white apical spots" — which is precisely the char- 

 acter of f/Iaucescens. The young are said to be " dark gray, as in glaucopteruH^' (of Kitt- 

 Wxz, ^ (jiancescens, Licht.) There is not the slightest likelihood that it is anything 

 more than <jlauctsctiis, probably In somewhat immature condition. 



LARUS MARmUS, Liau. 



Great Black-backed Gull. 



Lams marinns, LixN., Syst. Nat. i, 1766, 225.— Gm., Svst. Nat. i, 1788, 598.— Lath., Ind. 

 Orn. ii, 1790, 813.— Temm., Man, 1815, 490.— Boie, Isis, 1822, 562.— Steph., Gen. 

 Zool. xiii, 1826, 186.— Flem., Br. An. 1828, 140.— Bp., Syn. 1828, — ; List, 18.38, 

 63.— NuTT., Man. ii, 1834, 308.— Brehm., V. D. 1831,' 731.— Jen., Man, 1835, 

 278.— Eyt., Cat. 1836, 53.-AuD., Orn. Biog. iii, 1835, 305; v, 1839, 636; pi. 241 ; 

 Svn. 1839, 329; B. Am. vii, 1844, 172, pi. 450.— Naum., V. D. x, 1840, 439, pis. 

 268, 269.— Keys. & Blas., Wirb. Eur. 1840, 97.— Macgil., Man. Orn. ii, 1842, 

 244.— Gu?., B. L. L 1844, 361.— Schl., Rev. Crit. 1844, 124; Mus. P.-B. ix, 1863, 

 Lari, p. —.—Gray, Gen. of B. iii, 1849, 654 ; List Br. B. 1863, 231.— Lawr., B, 

 N. A. 1858, 844 ; Ann. Lye. N. Y. viii, 1866, 299.— Buy., Pr. Bost. Soc. viii, 1861, 

 72.— COUES, Pr. Phila. Acad. 1861, 244 ; ibid. 1862, 295; Pr. Ess. Inst, v, 1868, 

 306 ; Key, 1872, 312.— BoARDM., Pr. Bost. Soc. ix, 1862, 131.— Veer., Pr. Ess. 

 Inst, iii, 1862, 160.— Aelen, ibid, iv, 1864, 90.— Sharpe & Dress., B. Eur. pt. 

 XV, Dec. 1872. — RiDGW., Ann. Lye. x, 391 (Lake Michigan, Velie); and of authors. 



Leuciis marinns, Kaup, Sk. Eut. Eur. Thierw. 1829, 86. 



Dominicatnis marinns, Bruch., J. f. 0.1853,100; 1855, 280. — Bp., Consp. Av. ii, 1856, 

 213; Conipt. Rend, xlii, 1856, 770. 



Lams Jiifier, Briss., Oru. vi, 1760, 1.58. 



Larus nmrns, Linn., Syst. Nat. i, 1766, 225.— Gm., Syst. Nat. i, 1788, 598.— Lath., Ind. 

 Orn. ii, 1790, 814. 



Lams albns, MtJLL., Syst. Nat. Suppl. 1776, 108. 



Lams macnlatus, Bodd., Tabl. P. E. 1783, 16. 



Lams wiflj-miffs, Leach, Cat. 1816, 40. — Brehm, V. D. 1831, 728. 



Lams mulleri etfabricii, Brehm, V. D. 1831, 729, 730. 



DiAG. L. staturd maximus, palHo scMstaceo-nigro. Long. 30.00 ^?o?7. 



Hab. — American and European coasts of the Atlantic. South in winter to Long 

 Island (to Florida, And.). Great Lakes and the Mississippi (And.). 



Adnlf, breeding plumage. — Size very large ; general form strong, compact, aud power- 

 ful. Bill very stout, deep at the angle, rather short for its height; culmen toward the 

 end exceedingly convex, so much so as to make a tangent to it at the point where the 

 tip of the lower mandible touches it perpendicular to the commissure. Symphyseal 

 eminence very large aud prominent ; tarsus but little if any longer than the middle 

 toe and claw, compressed, rather slender for the size of the bird. Interdigital mem- 

 branes broad, scarcely emarginate. Bill bright chrome, the tip of both mandibles 

 diaphanous. A large bright vermilion spot occupies nearly the terminal half of the 

 lower mandible and encroaches a little on the upper. Edges of jaws bright vermilion. 

 Palate and tongue pale orange-red. Eyelids vermilion. Iris pale lemon-yellow. Legs 

 and feet pale flesh-color. Mantle intense slate-color, nearly black, with a purplish re- 

 flection. The secondaries and tertials broadly tipped with white, the line of demarca- 

 tion distinct. Primaries: Jirsi, black, scarcely lighter at its base, its tip white for 2^ 

 inches, its shaft white inferiorly, and sni>8riorly along the white portion of tbe feather ; 

 second, like the first, but its base lighter, the white tip less exteusive, and interrupted 

 by a narrow bar of black on one or both webs ; third, fourth, ffth, broadly tipped with 

 white, their bases of a lighter shade of slate than the second, and fading into white at 

 the junction with the bioud black subterminal band. 



Adult in winter. — As in summer, but the head and neck streaked with dusky. 



Yonng-of-the-ijcar. — As large as the adult ; the bill as large, but not so strong, nor the 

 eminence so well developed ; wliolly blade. Upper parts wholly dusky chocolate- 

 brown, mottled with whitish and 1 ght rufous, the latter on the back and wing.s, the 

 feathers being tipped and the wing coverts deeply indented with this color. Under 

 parts mottled with white or rufbus-white and dusky, the throat mostly immaculate. 



