HYDROCHELTDON LARIFORMIS, BLACK TERN. 705 



b. {American references.) 



Sterna sininamensis, Gm., Syst. Nat. i, 1788, 604. — Lath., Ind. Om. ii, 1790, 804 {Surinavi 

 Tern, Gen. Syu. vi, 352). 



Hiidrochelidon surinnmtnsis, Bp., Comptes Rendus, 1856, 773. 



Hi/drochdidon (Pelodcs) surniamensis, Gray, Haud-list, iii, 1871, 122, No. 11074. 



Sterna phimhea, Wils., Am. Orn. vii, 1813, 83. pi. 60, f. — (yoiiDg). — Pei.z., Novara 

 Reise, Orn. 155. 



Hydroclielidon plumhta, Lawr., B. N. A. 1858, 864.— Wheat., Ohio Agric. Rep. 1860, No. 

 277.— CouES & Pkext., Smiths. Rep. 1861, 418.-Hayd., Rep. 1862, 176.— Cab., 

 J. f. O. V, 232 (Cuba).— ScL., P. Z. S. 1864, 179 (Mexico).— Dress., Ibis, 18iJ6, 

 45 (Texas).— Sxow, B. Kans. 1873, 12. 



Sterna niqra, Bp., Syn. 1828. .355.— Sw. & Rich.*, F. B. A. ii, 1831, 415.— Nutt., Man. ii, 

 1834, 282.— AUD., Orn. Biog. iii, 1835, 593 ; v, 1839, 642 ; pi. 180 ; Syn. 1839, 

 320 ; B. Am. vii, 1844, 116, pi. 438.— DeKay, N. Y. Zool. ii, 1844, 300, pi. 126, f. 

 278.— GiR., B. L. I. 1844, 352.— HoY, Smiths. Rep. 1864, 438.— Trippe, Pr. Ess. 

 Inst, vi, 1871, 119 (Minnesota).— Aiken, P. Bost. Sec. xv, 1872, 210 (Colorado). 



Hydrochelidon nifirum, Bp., List, 1838, 61. 



EijdrocMldon fiWipcn, Coues, Pr. Phila. Acad. 1862, 554 (critical).— Coues, ibid. 1866, 

 99 (Colorado River) ; ihid. 1871, 46 (North Carolina, migratory). — Coues, Pr. 

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

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

 Ibis, 1864, 385 (the same).— Gundl., Rep. F. N. i, 1865, 393 (Cuba).— Lawi:., 

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

 (Massachusetts).— McIlwr., ibid, v, 1866, 96 (Canada).— Dale & Baxn., Tr. 

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

 1870, 157.— ScL. & Salv., P. Z. S. 1871, 573 (Middle America).— Allex, Bull. 

 M. C. Z. iii, 1872, 183 (Kansas, t&c). 



Sio-na fmipes, Turxu., B. E. Pa. 1869, 39. 



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



DiAG. S. nigra, dorso, alts, canduque plumhets, remigibus nigro-griseis rhachidibu'i albis, 

 crififio albo. 

 Ilah. — Europe, &c. North America generally. Ala.ska. Middle America. South 



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



linntal. 



Adult, breeding plumage. — The culmen is throughout exceedingly narrow, and trans- 

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

 TJk? bill is strongly compressed from the no.strils, causing the gonys as well as the 

 culmen 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 fdl 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 intercrural 

 space nearly till it. This space is very narrow and elongated. The tibia; are bare for 

 a moderate distance. The very short tarsus is quite smooth, being covered i)osteriorly 

 abd laterally with small, smooth, regular plates, anteriorly with eciually smooth tran.s- 

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

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

 the claw of the inner jn.st reaches to the base of the middle claw. The emargiuatiou 

 of the inner web extends to opj)osite 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 [loint, 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, i)nre l)laek. On the back of 

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

 gray or iilnmb»!ous, 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 th(; jtriniaries aro 

 whilisli, de<p( iiing into black at the tij)s. The primaries are blackish or dei|) pluni- 

 be<nis-gray, darkest on the outer web of the lirst, the inner webs of all. but cspoiially 

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

 primaries have a considerable amount ilf the ordinary silveriness. The under surl;u;e8 

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

 beous-wliite extending slightly over the edge of the wing on to the lesser eovert.s. The 

 long, full, under tail-coverts are pure white, iu marked contrast to the black t)f the 

 rest of the under jiarts. 



Adult, in winter plumage. — Very diilerent from the adult in summer. The forehe.-id, 



45 



