BIRDS OF NORTH AND MIDDLE AMERICA. 455 
Rhynchops nigra (not Linneus) Maximiian, Beitr. Naturg. Bras., iv, 1833, 877 
(Espirito Santo, s. Brazil).—Darwin, Zool. Voy. ‘Beagle,’ iii, 1839, 161 
(coast Uruguay); ed. 1841, iii, 143, part (habits)—Hartiaus, Index Azara’a 
Apunt., 1847, 26 (Paraguay).—_ Burmeister, Syst. Ueb. Th. Bras., iii, 1856, 
454; Journ. fiir Orn., 1860, 267 (Rio Parana, Argentina); Reis. La Plata, ii, 
1861, 250 (Rio Parana).—Satvin, Ibis, 1865, 193 (Acapam, Guatemala); 1866, 
200 (Acapam, Guatemala).—PruzeLn, Orn. Bras., 1870, 324, 461, part.— 
Sciater and Satvin, Proc. Zool. Soc. Lond., 1871, 566, part (monogr.).— 
Lawrence Mem. Bost. Soc. N. H., ii, 1874, 318 (San Blas, Tepic; Rio Zaca- 
tula, Colima).—Brrurrscn, Journ. fiir Orn., 1874, 279 (Santa Catarina, s. 
Brazil; synonymy; crit.); 1887, 37 (Rio Pilcomayo, Paraguay), 126 (Para- 
guay).—Wuire, Proc. Zool. Soc. Lond., 1882, 628 (Buenos Aires).—_SAUNDERS, 
Cat. Birds Brit. Mus., xxv, 1896, 153, part (Acapam, Guatemala, Jan.).— 
Satvin and Gopmay, Biol. Centr.-Amer., Aves, iii, 1903, 416, part (San Blas, 
Tepic; Rio Zacatula, Colima; San Mateo, Oaxaca?; Acapam, Guatemala), 
Rynchops nigra DurnForD, Ibis, 1877, 200 (Buenos Aires). 
Rhynchops melanura (not of Swainson) ScLater and Hupson, Argentine Orn., ii, 
1889, 193. 
Rhynchops intercedens SAUNDERS, Bull. Brit. Orn. Club, no. 25, March, 1888, 
p. xxvi (Sdo Paulo, s. e. Brazil; coll. Brit. Mus.); Cat. Birds Brit. Mus., 
xxv, 1896, 155 (So Paulo and Santa Catarina, s. e. Brazil; Buenos Aires, 
Argentina)—Kerr, Ibis, 1901, 236 (Gran Chaco, Paraguay).—Harrert, 
and Venturi, Novit. Zool., xvi, 1909, 254 (Avellaneda, etc., Argentina, 
Dec.; crit.). 
Rynchops intercedens HetuMayr, Novit. Zool., xv, 1908, 102 (Rio Araguaya, 
Brazil; crit.). 
[Rhynchops] intercedens SHaRPe, Hand-list, i, 1899, 138.—Forses and Rosinson, 
Bull. Liverp. Mus., ii, no. 2, 1899, 56. 
Rhynchops nigra intercedens IHERING, Revista Mus. Paulista, iii, 1899, 442 (Iguape, 
S4o Paulo, s. Brazil); iv, 1900, 106 (Sao Paulo); vi, 1904, 344 (Paraguay).-— 
Bertoni, Fauna Parag., 1913, 38. 
Rynchops nigra subsp. intercedens DaBBENE, Orn. Argentina, July 16, 1910, 212. 
RYNCHOPS CINERASCENS Spix. 
DUSEY-TAILED SKIMMER, 
Similar to R. nigra intercedens, but adults with under wing-coverts 
wholly deep sooty gray, axillars light gray, secondaries very narrowly 
tipped with white, and tail deep sooty, the rectrices (except middle 
pair) very narrowly edged with whitish. 
Adults in summer (sexes alike).—Forehead, entire loral, suborbital 
and malar regions and under parts immaculate white, shading into 
brownish gray or under tail-coverts which, however, are whitish on 
margins; axillars and proximal under wing-coverts light brownish 
gray, the remaining under wing-coverts much deeper brownish gray, 
becoming blackish along edge of wing, the inner webs of remiges 
deep brownish gray passing into dusky terminally; crown (including 
posterior portion of forehead), occiput, nape, hindneck, auricular and 
orbital regions (narrowly in front of and beneath eyes) and upper 
parts generally plain black or sooty black, the secondaries narrowly 
and not abruptly tipped with white, the lateral upper tail-coverts with 
