24 BULLETIN 86, UNITED STATES NATIONAL MUSEUM. 



d\ Size greater (wing averaging more than 180 mm.). 



Chordetles acutipemUs texensis. 

 d\ Size smaller (wing averaging less than 178 mm.), 

 e*. Lower parts darker, more heavily barred. 



Chordetles acutipennis acutipennis. 

 e^ Lower parts lighter, less heavily barred. 

 f. Smaller (wing averaging under 160 mm.) ; pale bars on under 

 side of tail more whitish; light bars on posterior lower parts 



averaging wider Chordetles acutipennis exilis. 



f. Larger (wing avei-aging over 165 mm.) ; pale bars on under side 

 of tail more buffy or ochraceous; light bars on posterior lower 

 parts averaging narrower. 

 g\ Light bars on tail broader ; size averaging larger. 



Chordetles acutipennis inferior, 

 g'. Light bars on tail narrower; size averaging smaller. 



Chordeiles acutipennis micromeris. 

 &. Smaller; wing speculum smaller, and buff or largely so; no white sub- 

 terminal bar on tail; throat-patch buff or ochraceous. (Females.) 

 d\ Large (wing usually more than 174 mm., averaging over 170 mm.). 



Chordeiles acutipennis texensis. 

 4^. Small (wing usually less than 168 mm., averaging under 170 mm.). 

 e\ Above darker; lower surface darker and posteriorly more heavily 



barred; size smaller Chordeiles acutipennis acutipennis. 



e^ Below paler; lower surface lighter and less heavily barred; size 

 greater. 

 f. Larger (wing averaging more than 166 mm.) ; light bars on tail 



broader Chordeiles acutipennis inferior. 



f. Smaller (wing averaging less than 163 mm.) ; light bars on tail 

 narrower. 

 g^. Posterior lower parts darker; size greater. 



Chordeiles acutipennis micromeris. 

 f/^ Posterior lower parts lighter ; size smaller. 



Chordeiles acutipennis exilis. 

 '. White or buffy patch on usually 5 outer primaries situated between the 

 tips of the seventh and tenth primaries ; primary coverts and outer webs 

 of primaries and of secondaries without spots or bars of buff or ochrace- 

 ous, or with at most faint markings; first primary usually longer than 

 second. (Chordeiles virginianus.) 

 &. Larger; alar speculum larger, and plain white without dusky markings; 

 a white subterminal bar on tail; gular crescent pure white; lower 

 parts less buffy. (Males.) 

 d^ Light mottlings of upper surface deeply tawny. 



e\ Posterior lower parts paler, more buffy or whitish; upper surface 

 — ~- lighter; size larger (wing averaging 199.7 mm.). 



Chordeiles vi>'ginianus henryi. 

 e*. Posterior lower parts darker, more ochraceous or tavmy; upper 

 surface darker; size smaller (wing averaging 168 mm.). 



Chordeiles virginianus minor, 

 d* Light mottlings of upper surface ochraceous buff or white, 

 e^. Smaller (wing usually less than 188 mm.). 

 f. Upper surface darker, the pale mottlings much less numerous. 



Chordeiles virginianus chapmani. 

 f. Upper surface lighter, the pale mottlings much more numerous. 



