712 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



CYPSELOIDES BRUNNEITORQUES BRUNNEITORQUES (Lafresnaye). 



CHESTNUT-COLLARED SWIFT. 



Adult male. — Pileum sooty black, the feathers along each side, 

 immediately above the lores, narrowly margined or edged with 

 whitish; lores deep black posteriorly, more sooty anteriorly; chin, 

 throat, and malar region dark sooty grayish brown; a broad collar 

 round neck deep cinnamon-rufous or chestnut-rufous, sharply defined 

 and clearer in color on hindneck, usually more or less broken on 

 foreneck by dusky center to feathers; remainder of upper parts 

 sooty black, of under parts deep sooty grayish brown; bill black; iris 

 dark brown; feet grayish brown or dusky (in dried skins); length 

 (skins), 112-131 (122); wing, 120-133 (126.7); tail, 40.5-51 (45.3); 

 exposed culmen, 5.5-6.5 (5.8); tarsus, 11-13 (11.9); middle toe, 

 7-8.5 (8).° 



Adult female. — Sunilar to the adult male but without the rufous 

 collar,^ which is entirely replaced by the general dark sooty color; 

 length (skms), 103-127 (116); wmg, 121-130 (125.1); tail, 40-48 

 (43.4); exposed culmen, 5.5-6.5 (5.9); tarsus, 11-12.5 (11.8); middle 

 toe, 7.5-8.5 (7.8).^ 



Young. — Similar to the adult female but texture of the plumage 

 different (softer) and general coloration somewhat paler, especially 

 on under parts, where, at least on flanks, abdomen, and under tail- 



« Seventeen specimens. 



b Among the seventeen specimens examined whose sex was determined as female 

 by their respective collectors are five which have the rufous collar, exactly as in 

 adult males. Whether these indicate that the female eventually attains the colora- 

 tion of the adult male, or that the sex was erroneously determined is a question; 

 but I incline to the latter view. 



c Twelve specimens. 



Locality. 



Middle 

 toe. 



M.\LES. 



Ten adult males from Costa Rica 



Four adult males from Guatemala (1) and Chiapas (3) 



Three adult males from Vera Cruz 



One adult male ( C. 6. griseifrons) from Tepic 



FEMALES. 



One adult female from Peru 



Nine adult females from Costa Rica 



One adult female from Chiapas 



One adult female from Oaxaca 



Two adult females ( C. 6. grisei/rons) from Tepic 



7.9 

 8.1 

 8 

 8.5 



8.5 

 8.2 



I am not able to discern any color differences between specimens from the different 

 localities (except iu case of those from Tepic). 



