344 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



AGELAIUS XANTHOMUS (Sclater). 

 YELLOW-SHOTJLDERED BLACKBIRD, 



AdAJilt male. — Uniform glossy black, with a faint bluish green reflec- 

 tion; lesser and ni'ddle wing-coverts clear lemon yellow, the latter 

 sometimes slightly paler (rarely inclining to white at tips); bill, legs, 

 and feet black; iris brown; length' (skin, one specimen), 198.1; wing, 

 107.2-108; tail, 83.8-86.9 (84.8); culmen, from base, 20.8-22.1; depth 

 of bill at base, 9.7; tarsus, 24.1-25.4;. middle toe, 19.6-19.8.' 



Admit femule. — Similar to the adult male in coloration, but smaller; 

 length (skins), 172.7-198.1 (185.4); wing, 95-97.3 (96.3); tail, 74.2-78.7 

 (77); culmen, from base, 19.8-20.3 (20.1); depth of bill at base, 8.1- 

 8.9 (8.6); tarsus, 24.1-24.9 (24.4); middle toe, 18.3.' 



Young. — Uniform dull black, except lesser wing-coverts, which are 

 light buffy yellow or yellowish buff, the middle coverts partly of the 

 same color. 



Iiiiinature. — Similar to adults, but yellow wing-patch more or less 

 broken posteriorly by spots or blotches of black. 



Island of Porto Rico, Greater Antilles. (Island of St. Thomas?) 



Agelaius dirysopterus Vieillot, Nouv. Diet. d'Hist. Nat., xxxiv, 1819, 539 part 



(St. Thomas, W. I.); Enc. M6th., ii, 1823, 713, part.— Gundlach, Anal. 



Soc. Esp. Hist. Nat., vii, 1878, 211 (Porto Rico); Jou'rn. fiir Orn., 1874, 312 



(Porto Rico); 1878, 177 (Porto Rico). 

 Agelieus chrysoplerus Sundevall, (Eiv. K. Vet.-Akad. Forh., 1869, 597 (Porto Eico). 

 [Agelseus'] dirysopterus Sclatee and Salvin, Nom. Av. Neotr., 1873, 37 (Porto Rico). 

 Icierus xanlhomus Sclater, Cat. Am. Birds, 1862, 131 ("Mexico;" coll. P. L. 



Sclater).— Taylor, Ibis, 1864, 168 (Porto Eico).— Bryant, Proc. Boat. Soc. 



N. H., X, 1866, 254 (Porto Eico). 

 Hyphantes xanlhomus Cassin, Proc. Ac. Nat. Sci. Phila., 1866, 63 (monogr.; Porto 



Eico; St. Thomas?). 

 Ageisms xanlhomus Sclater, Ibis, 1884, 12 (monogr.); Cat. Birds Brit. Mus,, xi, 



1886, 343. 

 [Agelteits} xanihomun Coky, List Birds W. I., 1885, 14. 

 Agelaius xanlhomus Cory, Auk, iii, Apr., 1886, 221; Birds W. I., 1889, 108; Cat. 



W. I. Birds, 1892 14, 110, 132 (Porto Rico; accidental onMonal.). 



Genus NESOPSAR Sclater. 



Nesopsar Sclater, Ibis, i, Oct., 1859, 457, footnote. (Type, Icterus nigerrimm 

 Osburn.) 



Rather small, uniformly black Icteridse with the bill longer than 

 the head, narrowly wedge-shaped, the wing about three times as long 

 as the culmen, rounded, the tail about two-thirds as long as the wing, 

 even, the tarsus about one-fourth as long as the wing. 



Bill longer than head, slender-conical or narrowly wedge-shaped, 

 compressed, acute, with straight outlines, its basal depth about one- 

 third the culmen, or less, its basal width less than the depth; culmen 

 straight, flattened, the flattened surface widening gradually toward 



' Two specimens. ^ Four specimens. 



