400 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



CALLIPHARUS NIGRIVENTRIS (Lawrence). 



BLACK-BELLIED HUMMING BIRD. 



Adult male. — Forehead, crown, and under parts velvety black, the 

 under tail-coverts white; occiput, hindneck, back, scapulars, and 

 wing-coverts metallic bronze-green, the upper tail-coverts duller and 

 more bronzy; four middle rectrices dusky bronze or dull blackish 

 glossed with bronze; three lateral rectrices (on each side) wdiite, 

 sometimes margined terminally with dusky; secondaries cinnamon- 

 rufous tipped with brownish dusky (the innermost with metallic 

 bronze-green); primaries dusky purplish bronze, the innermost 

 becoming cinnamon-rufous basally; primary coverts dusky; bill 

 black, the mandible more or less brownish (pale dull flesh color in 

 life) basally; iris dark brown; feet dusky (in life white, with scutella 

 pale brownish); length (skms), 72-87 (79); wing, 46-50.5 (48.3); 

 tail, 26.5-30 (27.9); culmen, 13.5-15 (14.5).« 



Adult female. — Above metallic bronze-green; four middle rectrices 

 dull greenish bronze or dull blackish, becoming bronzy basally; two 

 outer rectrices (on each side) white, the third mostly white, but with 

 more or less of dusky on edges, especially terminally; remiges dusky, 

 faintly tinged with purplish bronze, the secondaries and inner prima- 

 ries passing into cinnamon-rufous basally; under parts dull grayish 

 white or pale brownish gray, the sides and flanks mostly metalHc 

 bronze-green; bill, etc., as in adult male, but feet paler; length 

 (skins), 73-87 (79); wing, 44-47 (45.8); tail, 25.5-29 (27.1); culmen, 

 14.5-16 (14.9).^ 



Immature male. — Similar to the adult male, but forehead and crown 

 dull metallic bronze-green (instead of velvety black), and black of 

 under parts duller and more restricted, the under parts of body (except 

 medially) mostly dull dusky bronze-greenish. 



Costa Rica (Peorsnada; Naranjo de Cartago; Cervantes; La 

 Hondura; Coliblanco; Cariblanco de Sarapiqui) and western Panama 

 (Veragua: Lomo Lleno; Cordillera del Chucu; Calobre; Caribbean 

 slope Volcan de Chiriqui, 6,000-7,000 ft.). 



