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 Trinidad to 

 eastern Patagonia (Port Desire). 



(?) Sterna cayennetisis Leotaud, Ois. Trinidad, 1866, 535. 



[Sterna] cayennensis Gray, Iland-list, iii, 1871, 120, no. 11051, part (Venezuela). 



(?) [Phaethusa] cayennensis Heine and Reichenow, Nom. Mus. Hein. Orn., 1890, 

 355, part (Brazil). 



Sterna galericulata{notoi Lichtenstcin) Pelzeln, Orn. Bras., 1870, 324, 461— Sclater 

 and Salvin, 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. Miis.); Cat. Birds Brit. Mus., xxv, 1896, 

 85 (Venezuela; Bahia, ("amamu, Rio de Janeiro, Imbituba and Santa 

 Catarina, Brazil; Puerto Desiado e. Patagonia). — Chapman, Bull. Am. Mus. N. 

 H., vi, 1894, 84 (Trinidad).— Richmond, Proc. U. S. Nat Mus., xviii, 1896, 

 653 (Margarita Island, Venezuela^ crit.).— Cory, Pub. 137, Field Mus. N. H., 

 1909, 194 (Arul)a), 234 (Margarita Island).— Dabbene, Orn. Argentina, 1910, 

 211 (Puerto Desiado, e. Patagonia). 



[Sterna'] eurygnatha Sharpe, Hand-list, i, 1899, 135. — Forbes and Robinson, 

 Bull. Liverp. Mus., ii, no. 2, 1899, 54. 



Sterna curggnatha [error typ.] Ihering, Revista Mus. Paulista, iv, 1900, 294 

 (descr. eggs). 



o Saunders, Cat. Birds Brit. Mus., xxv, 1896, 85. 



