BIKD8 OP NORTH AND MIDDLE AMERICA. 603 



Immature male. — Length (skin), 137.16; wing, 74.93; tail, 58.1:2; 

 culmen, from base, 13.46; depth of bill at base, 10.16; width of max- 

 illa at base, 9.14; tarsus, 18.03; middle toe, 12.4.5.^ 



State of Oaxaca, southern Mexico (Tehuantepec City, Pluma, Hu- 

 allago, etc.). 



(?) Guiraca pareUina Sclater, Proc. Zool. Soc. Lond., 1859, 365 (Totontepec, 



Oaxaca) . 

 Guiraca parellina (not Cyanoloria pareUina Bonaparte) La-wrexoe, Bull. U. S. 



Nat. Mus., no. 4, 1876, 20, part (Tehuantepec City and Huallago, Oaxaca) . 

 P. [assffrina'] 'sumichrasti Ridgway, Man. N. Am. Birds, 1887, 447 (Tehuantepec 



City, Oaxaca; IT. S. Nat. Mus.). 

 Passerina sumichrasti Ridgway, Man. N. Am. Birds, 1887, 592; L'd ed., 1896, 614. 



Genus ORYZOBORUS Cabanis. 



Oryzohoma' Cabanis, Mus. Hein., i, June, 1851, 151. (Type, Losin. torrida 

 Scopoli, ^i. angolensis Jjinnsens.) 



Small dark-colored Fringillid^ with the bill enormously large and 

 thick, wing rather short and rounded, and tail shorter than wing and 

 much rounded. 



Bill enormously thick and broad at base, where its depth is equal 

 to or greater than the length of the exposed culmen, the width of the 

 mandible at base decidedly exceeding the distance from the nostril to 

 the tip of the maxilla; culmen and gonys nearly or quite straight; 

 commissure also nearly or quite straight to the subbasal deflection and 

 without notch near tip; culmen slightly or not at all ridged. Nostril 

 exposed, very small, circular. Rictal bristles small, situated midway 

 between rictus and nostrils. Wing moderate or rather short (three 

 and a half to a little more than four times as long as tarsus), rounded 

 (ninth primary shorter than fifth); primaries exceeding secondaries 

 by not more than distance from nostril to tip of maxilla. Tail shorter 

 than wing, much rounded, not more than half hidden by the upper 

 coverts, the rectrices broad, but somewhat pointed at tips. Tarsus as 

 long as or a little longer than culmen, its scutella distinct; middle toe 

 and claw about as long as tarsus, sometimes a little longer or shorter; 

 lateral claws reaching about to base of middle claw; hallux decidedly 

 shorter than lateral toes, its claw shorter than the digit. 



Colors. — Adult males black, with or without white spot at base of 

 primaries, or white under wing-coverts, or chestnut underparts; adult 

 females and young plain brown. 



Ra/nge. — Continental Tropical America, from southern Mexico to 

 southern Brazil and Ecuador. 



Of the four species examined, three {crassirostris, nuttingi, and 

 funereus) agree well in structure and coloration. The fourth {0. ang- 



'One specimen (the type), from Tehuantepec, Oaxaca. 

 ^ "Von opvZa, Reiss, und fiopoi, gefriissig." 



