76 BULLETIN 86, UNITED STATES NATIONAL MUSEUM. 



America. Winters in southern South America, south to Concepcion 

 del Uruguay, and Ysca Yacu in the Province of Santiago, northern 

 Argentina; and north to Chapada in Matto Grosso, central western 

 Brazil. 



Remarl^s. — Although the Florida nighthawk is commonly sup- 

 posed to be in color exactly like Chordeiles virginianiis virginianus, 

 it has certain color characteristics which are at least average, as the 

 above diagnosis indicates. The male of Chordeiles virginianus chajy- 

 Tnani differs from that of Chordeiles virginianus hesperis in. his 

 smaller size, darker, rather more blackish (less brownish), upper 

 parts, which have fewer light mottlings. From Chordeiles vir- 

 ginianU'S aseniensis he is distinguishable by his much darker upper 

 surface, the dark areas being more blackish, less grayish, brown, 

 with much less numerous light mottlings; and darker lower parts, 

 the dark areas anteriorly being more blackish, and the posterior por- 

 tion more heavily barred. 



The female, except, of course, for differences common to all the 

 subspecies, is almost identical with the male in color and markings 

 above, though averaging in general tone slightly more brownish; 

 but the posterior lower parts are more buff'y. She is similar to the 

 female of Chordeiles virginianus virginianus, but averages a little 

 less brownish (more blackish) on the upper surface, and somewhat 

 less buffy or ochraceous on the posterior lower parts. 



The first autumn plumage is practically identical with that of first 

 autumn Chordeiles virginianus vii-gimamis. Above this is much like 

 adult Chordeiles virginianus sennetti, and, indeed, occasional speci- 

 mens are scarcely distinguishable on the upper surf ace, though usually 

 the dark areas are more deeply blackish and the light markings finer. 

 It is also much like the adtdt of Chordeiles virginianus hesperis on 

 the upper surface, but lighter, the dark areas being less deeply black 

 (more grayish or brownish), more extensively and finely mottled 

 with whitish, particularly on back, scapulars, and tertials. 



Individual and seasonal variations in this race are practically the 

 same as in Chordeiles virginianus virginianus. 



There seems to be little geographical variation throughout the rather 

 extensive breeding range of this subspecies, for specimens from 

 southeastern South Carolina, Florida, southern Alabama, southern 

 Louisiana, and southeastern Texas are practically identical in both 

 size and color. A single example (No. 84251, U.S.N.M.) from Mount 

 Carmel, Illinois, taken, June 7, 1874, is, in measurements, nearer the 

 present race, though in color like Chordeiles virginianus virginianus, 

 but on the whole seems best referred to the former. A female from 

 Stuttgart, Arkansas, taken. May 13, 1910, is apparently typical Chor- 

 deiles virginianus ehapmani. A single male (No. 57904, U.S.N.M.) 

 from Macoiij North Carolina, collected, June 10, 1869, is surely of 



