270 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



depth of bill at base, 7.9-8.6(8.1); tarsus, 22.1-23.9 (23.1); middle toe, 

 15.2-17.3 (16.5).' 



Southeastern Mexico, in Slates of Guanajuato(?), Vera Cruz, (Cor- 

 dova, Jalapa), Oaxaca (Chihuitan, Tehuantepec, Totontepec, Santo 

 Domingo), and Chiapas, southward through Central America to the 

 Isthmus of Panama. 



Xanthornus prosthemelas Strickland, Jardine's Oontr. Orn., 1850, 120, pi. 62 

 (Guatemala; coll. H. Strickland). 



Icterus prosthemelas Sclatek, Proc. Zool. Soc. Lond., 1856, 301 (Cordova, Vera 

 Cruz); 1857, 7 (crit.); Cat. Am. Birds, 1862, 132 ("Central America"); Cat. 

 Birds Brit. Mus., xi, 1886, 373 ( Corogal and Belize, British Honduras; Choc- 

 tum, Vera Paz, and sources Rio de la Pasion, Guatemala; San Pedro, Hon- 

 duras; Peje and Tucurriqui, Costa Rica).— Sclatee and Salvin, Ibis, 1859, 

 20 (Guatemala); Proc. Zool. Soc. Lond., 1867, 279 (BlewfieldsR., Nicaragua); 

 1870, 837 (San Pedro, Honduras).— Mooke, Proc. Zool. Soc. Lond., 1859, 58 

 (Comayagua, Honduras). — (?) Dur.EsLaNaturaleza, i, 1868,139 (Guanajuato, 

 Mexico).— La whence. Bull. U. S. Nat. Mus., no. 4, 1876, 23 (Chihuitan, 

 Oaxaca). — Boixard, Proc. Zool. Soc. Lond., 1878, 59 (Naranjo, Costa Rica).— 

 Zeledon, Cat. Aves de Costa Rica, 1882, 9; An. Mus. Nac. Costa Rica, i, 1887, 

 112 (Jimenez; Naranjo de Cartago). — Ridgway, Proc. U. S. Nat. Mus., x, 

 1887, 580 (Truxillo, Honduras); x, 1888, 588 (Segovia R., Honduras).— Sal- 

 vin and GoDMAN, Biol. Centr.-Am., Aves, i, 1887, 466. — Richmond, Proc. 

 U. S. Nat. Mus., xvi, 1893, 495 (Rio Escondido, Nicaragua). 



llcieriin'] prosthemelas Sclater and Salvin, Nom. Av. Neotr., 1873, 36. 



Ilderusl prosthemelas Ridgway, Man. N. Am. Birds, 1887, 375. 



Icterus domliiirensis, var. prosthemelas Baihd, Brewer, and Ridgway, Hist. N. 

 Am. Birds, ii, 1874, 182. 



' Nine specimens. 



Specimens from different localities average as follows: 



As a rule, specimens from Honduras and Nicaragua have more black on the under 

 parts, that of the anterior portions extending farther backward (sometimes covering 

 entire breast), the sides and flanks more or less clouded or otherwise marked (some- 

 times heavily) with black. The series is not complete enough, however, to show 

 whether there are constant differences. 



