BIRDS OF NORTH AND MIDDLE AMERICA. 89 
Range.—Southwestern Costa Rica to Cayenne and Ecuadér. (Two 
species. )* 
MICROBATES CINEREIVENTRIS SEMITORQUATUS (Lawrence). 
HALF-COLLARED ANTWREN. 
Adults (sexes alike) —Pileum and hindneck plain 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 extending more 
or less over sides of neck; lores dull whitish broken by dusky bristle- 
like tips to feathers; anterior portion of malar region whitish; chin 
and throat white 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 (18.6).® 
Adult jfemale—tLength (skins), 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 (Jiménez; San Carlos; La Balsa; Rio Sticio; Pacuare; 
Guipiles; Gudcimo; Cudbre; El Hogar; Carrillo; La Vijagua) 
and Panam4 (Volcan de Chiriqui; Santiago de Verégua; Lion Hill; 
Panamé4); Colombia (Antioquia) ? 
Ramphocenus semitorquatus Lawrence, Ann. Lyc. Nat. Hist. N. Y., vii, 1862, 469, 
(Lion Hill Station, Panam; coll. G. N. Lawrence); ix, 1868, 108.(‘‘Valza,’’?. e. 
La Balsa, Costa Rica; crit.).—Sauvin, Proc. Zool. Soc. Lond., 1867, 145 (San- 
tiago de Verfgua, Panamé4; crit.); 1870, 195 (Calovévora, Panam4).—FRAnt- 
aius, Journ. fir Orn., 1869, 305 (Costa Rica).—Boucarp, Proc. Zool. Soc. 
Lond., 1878, 61 (San Carlos, Costa Rica).—Zxztep6én, Anal. Mus. Nac. Costa 
Rica, i, 1887, 115 (Rio Sticio, Costa Rica). 
@T 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. 
6 Thirteen specimens. 
¢ Ten specimens, from Costa Rica. 
rf ‘i ; Cul- Tar- | Middle 
Locality. Wing. | Tail. | sen, sus. toe. 
MALES, 
Ten adult males from Costa Rica............2..2-.2-0e eee eee 53.9 27.6 18.1 23.7 13.6 
Two adult males from western Panamé (Chiriquf)..........-.. 53.7) 28.7 18.5 23 13 
One adult male from eastern Panama (line of railway)...--..-. 54° "2608 |onnwaawe 22.5 14 
