504 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Several species generally referred to this genus (or to Caprimidgus 

 by those who do not recognize Antrostomus as distinct) I have not 

 been able to examine. These are: A. maculicavdus (Lawrence), A. 

 'pwnmlus (Gould), A. wMtelyi Salvia, and A. sericeocaudaius Cassin. 

 An examination of these might necessitate some modification of the 

 generic diagnosis, or, on the other hand, the elimination of one or 

 more of the species mentioned from the genus." 



Notwithstanding the several pronounced structural diflPerences 

 between the type of Antrostomus and aU the other species here 

 referred to that genus, I am not able to subdivide the genus satis- 

 factorily. A. carolinensis differs from all the rest in the pinnate 

 rictal bristles, wing-formula (the ninth primary being distinctly 

 longer than the eighth instead of the same length, the tenth very 

 much longer than the seventh instead of being the same length or 

 slightly shorter), in having the outer web of only the eighth and 

 ninth (instead of seventh, eighth, and ninth) primaries sinuated, in 

 having the hallux (with claw) much longer than the basal phalanx of 

 the middle toe, and possibly in other characters.'' A. rufus (Bod- 

 daert) is, however, so exact a reproduction of A. carolinensis in 

 coloration and large size that, notwithstanding the absence of pinnse 

 to the rictal bristles, its different wing-formula, etc., it would seem 

 unreasonable to separate the two genericaUy. In fact, A. rufus 

 has the feet more as in A. carolinensis, the anterior toes being even 

 relatively shorter and stouter, instead of the reverse as seen in other 

 species. 



KEY TO THE SPECIES AND SUBSPECIES OF ANTROSTOMTTS. 



a. Eictal bristles with distinct lateral filaments; wing 201.5-225 mm. (Southeastern 

 United States, south in winter to Greater Antilles, Panama, and Colombia.) 



Antrostomus carolinensis (p. 506). 



aa. Rictal bristles without lateral filaments; wing less (usually much leas) than 



200 mm. 



6. General color strongly rufescent brown, the wing 177-194 mm. ; adidt males with 



terminal half of inner web of lateral rectrices ochraceous or tawny on under 



surface, white margined with ochraceous or tawny on upper surface; adult 



females with lateral rectrices tawny at tip. (Antrostomus rufus.) 



a Of the American species listed under Ca-primulgus ia Sharpe's "Hand-list" (ii, 

 1900, 84, 85), C. Tosmbergi Hartert, said to be nearly related to " Caprimulgus " ocellatus 

 Tschudi, is probably a Nyctipkrynus (see p. 493); C. yucatanicMS Hartert is the type 

 of the genus Nyctagreus Nelson, very closely related to Otophones Brewster and pos- 

 sibly not distinct genericaUy from that remarkable form. 



b According to Hubert Lyman Clark, in Auk, xviii, 1901, 169, 171, A. carolinensis 

 differs from all other North American Caprimulgidse in possessing 14 secondaries; but 

 I am able to find only 12, the same number as in A. vociferus and others. The same 

 authority gives the wing-formula of A. carolinensis as 8, 7, 9, 6, 5, 4, 3, 10, 2, 1, which 

 is impossible, for no member of the Caprimulgidse, so far as I am aware, has the tenth 

 primary shorter than the third. A perfect 'specimen now before me has the wing- 

 formula as follows: 9, 8, 10, 7, 6, 5, 4, 8, 2, 1. 



