BIRDS OF NORTH AND MIDDLE AMERICA. 89 



Range. — Southwestern Costa Rica to Cayenne and Ecuador. (Two 

 species.)'* 



MICROBATES CINEREIVENTRIS SEMITORQUATUS (Lawrence). 



HALF-COLLARED ANTWREN. 



Adults (sexes alike). — Pileum and hindneek jilain warm-sepia 

 brown; rest of upper parts plain sepia, the edges of greater wing- 

 coverts and secondaries (especially the tertials) more rufescent, the 

 rectrices decidedly darker terminally; sides of head (except lores) 

 plain ochraceous-buff to deep tawny-buff, this color extendmg more 

 or less over sides of neck; lores dull wliitish broken by dusky bristle- 

 like tips to feathers; anterior portion of malar region whitish; chin 

 and throat wliite or grayish white, the latter bordered along each 

 side by a broad but more or less broken streak of black; rest of 

 under parts plain gray (no. 6 to mouse gray) passing into olive on 

 flanks and under tail-coverts, the upper chest broadly streaked 

 with black; maxilla brownish black with paler tomium, mandible dull 

 whitish (horn color, flesh color, or straw yellowish in life) ; iris brown; 

 legs and feet horn color (dark bluish gray in life). 



Adult male.— Length (skins), 95-106 (100); wing, 51-57 (53.9); 

 tail, 26.5-29.5 (27.7); culmen, 17.5-19 (18.1); tarsus, 22-24.5 (23.7); 

 middle toe, 13-14.5 (13.6).^ 



Adult Jemale.— Length (sldns), 92-101 (96); wing, 50.5-53.5 

 (51.5); tail, 24-28 (26.3); culmen, 17-19 (18.1); tarsus, 20.5-24.5 

 (23.1); middle toe, 12.5-13.5 (12.9).^= 



Costa Rica (Jimenez; San Carlos; La Balsa; Rio Sucio; Pacuare; 

 Guapiles; Guacimo; Cuabre; El Hogar; Carrillo; La Vijagua) 

 and Panama (Volcan de Chiriqui; Santiago de Venigua; Lion Hill; 

 Panama) ; Colombia (Antioquia) ? 



RampJiocxnus scmitorquatus Lawrence, Ann. Lye. Nat. Hist. N. Y., vii, 1862, 469^ 

 (Lion Hill Station, Panama; coll. G. N. Lawrence); ix, 1868, 108 ("Valza," i. e. 

 La Balsa, Costa Rica; crit.). — Salvin, P^oc. Zool. Soc. Lond., 1867, 145 (San- 

 tiago de Veragua, Panamd; crit.); 1870, 195 (Calovevora, Panama). — Frant- 

 zius, Journ. fiir Orn., 1869, 305 (Costa Rica). — Boucard, Proc. ZooL Soc. 

 Lond., 1878, 61 (San Carlos, Costa Rica). — Zeledon, Anal. Mus. Kac. Costa 

 Rica, i, 1887, 115 (Rio Sucio, Costa Rica). 



°' I have not seen M. collaris (Pelzeln), the type of the genus, and the above generic 

 description is drawn up from M. cinereiventris and its subspecies semitorquatus. 

 b Thirteen specimens. 

 c Ten specimens, from Costa Rica. 



