HYDEOCHELIDON LAKIFORMIS, BLACK TERN. 705 



b. {American references.) 



Shrna siirinamcnsis, Gar., Syst. Nat. i, 17^8, C04. — Lath., lod, Orn. ii, 1790, 804 (Surinam, 



Tern, Gen. Syn. vi, 352). 

 HildrocluUdon surinnmtnsis, Bp., Comptes Renilus, 1856, 773. 

 Bjjdrochelidoii (Pelodcs) surniamensis, Ghay, Hund-list, iii, 1871, 122, No. 11074. 

 Sterna pi umhea, WiLS., Am. Orn. vii, 1813, 83. pi. CO, f. — (young). — Pelz., Novara 



Reise, Orn. 155. 

 Hydroclielidon plumbca, Lawr., B. N. A. 1858, 864. — Wheat., Ohio Agric. Eep. 1860, No. 

 277.— COUES & PiiEN'T., Smiths. Rep. 1861, 418.-Hayd., Ru.p. 1802, 176.— Cab., 

 J. f. 0. V, 232 (Cuha).-SCL., P. Z. S. 1864, 179 (Mexico).-Di!ESS., Ibis, 1866, 

 45 (Texas).- Snow, B. Kans. 1873, 12. 

 Stei-na nigra, Bp., Syn. 1828. 355.— Sw. & Eicii., F. B. A. ii, 1831, 415.— Nutt., Man. ii, 

 1834, 282.— Atjd., Orn. Biog. iii, 18:i5, .''.93; v, ]8;;0, 642; pi. 180; Syn. 1839, 

 320 ; B. Am. \-ii, 1844, 110, pi. 438.— DeKav, N. Y. Zool. ii, 1844, 300, pi. 126, f. 

 278.— GiR., B. L. I. 1844, 352.— Hoy, Smiths. Rep. 1864, 438.— Trii-pe, Pr. Ess. 

 Inst. Ti, 1871, 119 (Minnesota).- Aiken, P. Boet. Soc. xv, 1872, 210 (Colorado). 

 Hydrochelidou nigrum, Bp., List, 1838, 61. 



Bydroclielidon fissipes, Codes, Pr. Phila. Acad. 18G2, 554 (critical). — Coues, iiid. 1866, 

 99 (Colorado River) ; ibid. 1871, 46 (North Carolina, migratory).- CouE.s, Pr. 

 Ess. Inst. V, 1868, 309 (New Euglaud).— Coues, Pr. Bost. Soc. xii, 1868, 127 

 (South Carolina, in summer). — Coues, Ibis, 1864, 391 (Honduras). — Salv., 

 Ibis, 1864, 385 (the same).— Gundl., Rep. F. N. i, 18C5, 393 (Cuba).— Lawk., 

 Ann. Lye. N. Y. viii, 1866, 299 (New York).— Ali.en, Pr. Ess. Inst, iv, 1864, 91 

 (Massachusetts).— McIlwr., ihid. v, 1866, 96 (Canada).— Daix & Bann., Tr. 

 Cbic. Acad. 1869, 307 (Alaska).— Allen, Am. Nat. iii, 1870, 644.— Mayx., Guide, 

 1870, 157.— ScL. & S.\LV., P. Z. S. 1871, 573 (Middle America).— Allen, Bull. 

 M. C. Z. iii, 1872, 183 (Kansas, .fcc). 

 Slerna fissipes, TURNB., B. E. Pa. 1869, 39. 



Sterna "frenata," Salv., Ibis, 1860, 278 (error ; see Ibis, 1866, 205). 



Dug. S. nigra, dorso, alis, cauddque plumleis, remigiius nigro-griseis rhacliidiiu^ alMs, 

 crisso alio. 



Sab. — Europe, &c. North America generally. Alaska. Middle America. South 

 America to Chili. Breeds at large in North America. Winters chiefly or entirely extra- 

 limital. 



Adult, breeding plumage. — The cnlmen is throughout exceedioglj' narrow, and trans- 

 versely very convex, even at the the base it being scarcely at all broadened or flattened. 

 The bill is strongly compressed from the nostrils, causing the gonys as well as the 

 cnlmen to bo very sharp and narrow. The nasal fossa is notably short, becoming 

 obsolete rather abruptly, and in the middle of the upper mandible. The nostrils 

 nearly fill its whole length, are pretty large and wide, of ordinary general character- 

 istics. The feathers on the sides of the mandible extend but little further than on the 

 culmen, and have a broad rounded outline. Those on the submental or intercrnral 

 space nearly fill it. This space is very narrow and elongated. The tibiae are bare for 

 a moderate distance. The very short tarsus is (|uito smooth, being covered posteriorly 

 and laterally with small, smooth, regular plates, anteriorly with equally smooth trans- 

 verse scutella. The toes are very long, the middle one without its claw fully equal- 

 ing the tarsus. The outer is as long as, perhaps even slig.htly exceeding, the middle; 

 the claw of the inner just reaches to the base of the middle claw. The emarginatiou 

 of the inner web extends to opposite the second articulation of the middle toe, that of 

 the outer to the middle of the second phalanx of the same toe. The claws are all 

 moderately arched, slender and compressed, acute, the inner edge of the middle one 

 but slightly dilated. The remiges and rectrices are notable for their great breadth,, 

 and neither tapers to a very acute point, but are rather broad to near the apices, 

 which .are rounded. The inferior caudal tectrices are very long and full. 



Head and neck all round, and under parts to the vent, pure black. On the back of 

 the neck, and between the "shoulders, the black becomes gradually changed into leaden- 

 gray or plumbeous, which extends undiluted to the very apices of the tail feathers.. 

 The tertials are of the same color as the back ; the secondaries even a little darker, 

 tending toward the color of the primaries. The shafts of all the primaries are 

 whitish, deepening into black at the tips. The primaries are blackish or deep plum- 

 beous-gray, darkest on the outer web of the first, the inner webs of all, but especially 

 the outer one, fading into lighter on their margins. The superior surfaces of all the 

 primaries have a considerable amount of the ordinary silveriuess. The under surfaces! 

 of the wings are white, but considerably deepened by a iflumbeous wash, this plum- 

 beous-white extending sligjitly over the edge of the wing on to the lesser coverts. The 

 long, full, under tail-coverts are pure white, in marked contrast to the black of the 

 rest of the under parts. 

 Adult, in winter plumage. — Very different from the adult in summer. The forehead, 



45 



