604 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



olensis^ type of the genus) differs in proportionally smaller, narrower, 

 and more acute bill and in having chestnut under parts, 



KEY TO THE SPECIES OF ORYZOBORUS. 



a. Larger (wing 64.77-71.88, exposed culmen 17.27-19.05); bill pale brownish or 

 (lull whitish in adult male more or less dusky in female and young. (Eastern 

 Nicaragua. ) Oryzoborus nuttingi (p. 604) 



aa. Smaller (wing 53.09-57.91, exposed culmen 12.70-13.97) ; bill black in both ibexes. 

 (Southern Mexico to Isthmus of Panama.) Oryzoborus funereus (p. 605) 



ORYZOBORUS NUTTINGI Ridgway. 

 NTITTING'S RICE GROSBEAK. 



Adult male. — Entireh" uniform deep black, including under wing- 

 coverts and axillars; inner webs of primaries dusky grayish, becoming 

 paler, but not inclining to white, basally; bill wholl}" pale brownish or 

 brownish white; legs and feet dusk}'; length (skins), 140.97-149.86 

 (146.30); wing, 66.04-71.88 (69.34); tail, 63.25-66.55 (65.28); exposed 

 culmen, 17.27-19.05 (18.03); depth of bill at base (two specimens), 

 16.51-17.53 (17.02); tarsus, 18.29-19.05 (18.80); middle toe, 14.22- 

 15.24 (14.73).^ 



Adult female. — Above uniform deep brown (intermediate between 

 mummy brown and raw umber); beneath uniform raw-umber brown, 

 vaiying to deep cinnamon-brown or russet; bill dusky, sometimes 

 nearly black; length (skins), 126.75-133.86 (130.30); wing, 64.77-66.29 

 (65.53); tail, 60.96-61.98 (61.47); exposed culmen, 17.27-17.78(17.53); 

 depth of bill at bare, 17.27; tarsus, 18.03-19.05 (18.54); middle toe, 

 13.97-14.48 (14.22).^ 



Immature male. — Similar in coloration to the adult female, but 

 darker, the upper parts rich bistre brown (remiges ana rectrices clove 

 brown), the under parts deep russet-brown, paler (inclining to cinna- 

 mon) on chin and abdomen. 



Immature female. — Similar to the adult female, but under parts less 

 tawny brown (nearly raw umber), and tertials margined with light 

 rusty. 



Eastern Nicaragua (Los Sabalos, Grey town, Escondido River, etc.). 



Oryzoborus nuttingi Ridgway, Proc. U. S. Nat. Mus., vi, Apr. 11, 1884, 401 (Los 

 Siibalos, e. Nicaragua; U. S. Nat. Mus. ). — S.\lvin and Godman, Biol. Centr.- 

 Am., Aves, 1, 1885, 348.— Sharpe, Cat. Birds Brit. Mus., xii, 1888, 80.— 

 Richmond, Proc. U. S. Nat. Mus., xvi, 1893, 491 (Greytown and Rio Escon- 

 dido, e. Nicaragua). 



^ Five specimens. 



^ Two specimens, one of them immature though full grown. 



