636 LARUS DELAWARENSIS. RING-BILLED GULL. 



organization, weaker bill, &c., it shows an evident approach to the "Mew-Gnlls" 

 (delawarensis, canuii, &c.), niHl apparently connects the latter gronp with larger Herring- 

 Gulls with flesh-colored feet. But the liability to error in giving the colors of the fi-et, 

 &c., of water birds, is very great; l\Ir. Lawrence himself (B. N. A. p. 840) stating that 

 the legs are " Hesh-colored," although their tint was correctly given by hiiu when 

 introducing the species. 



For a more extensive discussion of the point, I refer to my paper in the Philadelphia 

 Academy "Proceedings." While it is probable that Richardson's name refers to the 

 species described by Mr. Lawrence, I by no means insist upon this identification, nor 

 would wish to supersede the name caJlfornicus. 



Comparison of L. califoniiciis iiilh the Euroi)ean L. ar«/cntatus. — The terminal markings 

 of the primaries of the two are identical, and in size the species are not very dissimilar. 

 The color of the feet is strikingly diverse (dusky greenish in califonticm ; tlesh-cclored 

 in anjeiitaius) ; and the picture of the bases of the primaries very different, as follows : 

 In valifoniicKS the bluish color is very light in tint, in fact almost white ternjinally ; 

 extends very far along the feathers (especially on the first quill), its edge ijarallel with 

 the rhachis for nearly its whole length, and then it turns suddenly off at an acute 

 angle, running up nearly as far on the edge as in the centre of the inner vane of the 

 feather. In argentaius the color is but little, if any, lighter than the mantle; it ex- 

 tends along the feather with an outline oblique to the shaft ; runs up much further in 

 the centre of the inner web than along its edge, along which latter the black descends 

 a little way as a narrow marginal line. In californicns the line of demarcation of the 

 two colors is much more trenchantly marked than it is in argentatus. 



LARUS DELAWARENSIS, Ord. 



Ring-billed Gull. 



Larus delaumrensis, Ord, Guthrie's Geog. 2d Am. ed. ii, 1815, 319. — Lawr., B. N. A. 1858, 

 846; Ann. Lye. N. Y. viii, 1866, 299.— Coop. & Suck., N. H. Wash Ter. 1860, 

 273 —Wheat., Ohio Agric. Rep. 1860, No. 267.— Coues, Pr. Phila. Acad. 186L, 

 246; 1862, 302.— Coues, Smiths. Rep. 1861, 418.— Verr., Pr. Ess. Inst, iii, 1862, 

 160.— Boardm., Pr. Bosit. Soc. ix, 1862, 131.— Schl., Mus. P.-B. iv, 1863, Lari, p. 

 22.— Allen, Pr. Ess. Inst, iv, 1864, 80.— Coues, Pr. Bost. Soc. xii, 1868, 126.— 

 TuRNB., B. E. Pa. 1869, 38.— Coues, Pr. Phila. Acad. 1871, 39.— Coues, Key, 

 1872, 313.— RiDGW., Ann. Lye. N. Y. x, 1874, 38 (Illinois). 



Larus canus, Bp., Syn. 1828, 259. Not of authors. 



Larus zonorhynchus, Rich., F. B. A. ii, 1831, 421.— Nutt., Man. ii, 1834, 300.— AuD., Orn. 

 Biog. iii, 1835, 98 ; v, 1839, 638 ; pi. 212 ; Syn. 1839, 327 ; B. Am. vii, 1844, 152, pi. 



, 446.— GiR., B. L. I. 1844, 360.— Bp., Comptes Rendus, 1856, 771 ; Consp. Av. ii, 



1856, 224.— Blas., J. f. O. 1865, 380. 



Larus zonorhjjuchns var. bruchii, Bp., Consp. ii, 1856, 224. 



Larus zonorhijnclms var. mexicaiius, Bp., Consp. ii, 1856, 224. 



Glaucus zonorhynchus, Bruch, J. f. O. 1853, 102. 



Gaviua zonorhyndia, Bp., Naum. iv, 1854, 202.— BiJUCH, J. f. O. 1855, 282. 



Gavina brnchii, Bp., Naum. iv, 1854, 202.— Bruch, J. f. O. 1855, 283. 



DiAO. L. rostra nigrocincto, palKo coeruleo-perlaceo, remige primo spatio subapicali albo, tarso 

 dlgito medio longiore. 



jjab. — North America generally; throughout the interior as well as coastwise. Cuba 

 (Cab., J. f. O. V, 236). 



Adult in summer.— JiUl rather stout, as long as the middle toe and claw ; the upper 

 mandible considerably convex at the end ; under mandible much thickened at the 

 angle, which is prominent ; the outline from base to angle, and from angle to tip, both 

 concave. Middle toe and claw scarcely more than three-fourths the tarsus. Bill 

 greenish-yellow, at tip chrome, encircled at the angle with a broad band of black. 

 Legs and feet dusky bluish-green. Mantle light pearl-blue, fading into white at the 

 ends of the secondaries and tertials, the line of demarcation indistinct. Primaries: 

 first black, the basal portion of the inner web very light bluish-white, almost pure, 

 with a spot of white about 1.25 inches long near the end, of equal extent on both webs, 

 divided by the black shaft ; second with a small white spot on the inner web, an(l the 

 inner web whitish at base for a longer distance ; the whitish of the bases of the prima- 

 ries regularly increases inward and the black decreases, until on the sixth it is merely 

 a transverse bar. Apex of first primary black, of others white, the spot being very 

 minute ou the second, and gradually increasing; seventh and innermost prmiaries 

 without any black, like the secondaries. 



Adult in winter.— As in summer, but the head and neck behind spotted (not streaked 

 nor nebulated) with dusky. 



Young, first iti«^er.— Upper parts irregularly mottled with dusky brown and the pearl- 



