BIRDS OF NORTH AND MIDDLE AMERICA. 475 
and postocular (supra-auricular) region dull black, the feathers mar- 
gined, more or less distinctly, with grayish white; hindneck, upper- 
back, rump, and upper tail-coverts white, the rump more or less 
spotted with gray; scapulars and interscapulars pale gray, indis- 
tinctly though rather broadly margined terminally with white, the 
tertials similar but darker gray centrally; anterior lesser wing-coverts 
(except along edge of wing) gray, the feathers darker centrally, form- 
ing a well-defined broad stripe across anterior portion of wing; pos- 
terior lesser coverts immaculate white; middle and greater coverts 
white basally, terminally, and along edges, gray centrally; secondaries 
dark gray (more or less silvery or “frosted”’), tipped and distally 
edged with white, their inner webs mostly white; primaries dark gray, 
“frosted”’ with lighter gray, margined terminally with white, their 
inner webs broadly edged with white, except the longer (distal) quills; 
primary coverts similar but margined terminally with pale gray; 
middle pair of rectrices pale gray (more whitish on inner webs), tipped 
and terminally edged with white; outermost rectrices white to near 
‘tip, where gray and blackish, the intermediate rectrices white proxi- 
mally, gray and dusky distally and margined with white at tips; sides 
of head (beneath eyes) and entire under parts, together with axillars 
and whole under surface of wing (except a broad stripe of deep gray 
along shafts on inner webs of primaries) immaculate white. 
Downy young.— Grayish white, thinly streaked with dark gray on 
the crown, behind the eye, and on the upper parts generally; under 
parts white; bill olivaceous; trasi and toes brown, claws lighter.” ¢ 
Atlantic coast of South America, from Colombia (Burilaca, Santa 
Marta) and Islands of Margarita, Aruba, Tobago, and Triniddd to 
eastern Patagonia (Port Desire). 
(?) Sterna cayennensts Liotaup, Ois. Trinidad, 1866, 535. 
[Sterna] cayennensis Gray, Hand-list, iii, 1871, 120, no. 11051, part (Venezuela). 
(?) [Phaéthusa] cayennensis Heine and ReicHENow, Nom. Mus. Hein. Orn., 1890, 
355, part (Brazil). ; 
Sterna galericulata(not of Lichtenstein) PezEn, Orn. Bras.,1870,324, 461—ScuaTER 
and Satvin, Proc. Zool. Soc. Lond., 1871, 568-9, part. 
Sterna eurygnatha SAUNDERS, Proc. Zool. Soc. Lond.,’ 1876 (pub. Oct. 1), 654 
(Santa Catarina, s. Brazil; coll. Brit. Mus.); Cat. Birds Brit. Mus., xxv, 1896, 
85 (Venezuela; Bahia, Camamu, Rio de Janeiro, Imbituba and Santa 
Catarina, Brazil; Puerto Desiado e. Patagonia). —Cuapman, Bull. Am. Mus. N. 
H., vi, 1894, 84 (Trinidad).—Ricumonp, Proc. U. 8. Nat Mus., xviii, 1896, 
653 (Margarita Island, Venezuela; crit.).—Cory, Pub. 187, Field Mus. N. H., 
1909, 194 (Aruba), 234 (Margarita Island).—Daxnsrne, Orn. Argentina, 1910, 
211 (Puerto Desiado, e. Patagonia). 
[Sterna] eurygnatha SHarre, Hand-list, i, 1899, 135.—Forses and Rosinson, 
Bull. Liverp. Mus., ii, no. 2, 1899, 54. 
Sterna curggnatha [error typ.] InERING, Revista Mus. Paulista, iv, 1900, 294 
(descr. eggs). 
@ Saunders, Cat. Birds Brit. Mus., xxv, 1896, 85. 
