THE GENUS CHOKDEILES SWAINSON — OBERHOLSEE. 97 



tail-bars are more deeply ochraceous. The light extreme of both 

 gray and ochraceous phases is characterized by a general reduction 

 of the black areas on the upper parts and a consequent increase of 

 light areas, and by narrower black bars on the posterior lower surface. 

 The dark extreme of both phases has much black above and heavier 

 black bars and mottling below. 



The full-grown young bird in gray phase first autumn plumage is 

 superficially very similar to the corresponding stage of Chordeiles 

 vh'gi7iianus hesperis, but it is more finely mottled above, is smaller, 

 and, of course, readily distinguishable by the position of the white 

 or buff patch on the wing-quills. 



The earliest name for any form of this species is Caprimulgus 

 acutipennis Boddaert,^ which has for its basis the " Crapaud-volant 

 ou Tette-chevre, de la Guiane " of d'Aubenton ; ^ and " L'Engoule- 

 vent acutipenne de la Guyane " of Buffon,' both of which apply ex- 

 clusively to the bird from the Guianas. Berlepsch and Hartert have 

 further restricted the type-locality to Cayenne, French Guiana.* 

 The next name to be applied to this race is Caprimulgus hi^asilianus 

 Gmelin,^ the type-locality of which is Brazil. Should it, therefore, 

 ever become advisable to separate subspecifically the Brazilian bird 

 from that of the Guianas, as is possible on account of its apparently 

 greater size, its name will be Chordeiles' acutipennis hrasilianus 

 (Gmelin). The remaining synonyms of Chordeiles acutipennis acuti- 

 pennis need no further elucidation; but it may be well to mention 

 that Caprimulgus hirundinaceus^ which usually appears in the 

 synonymy of Chordeiles acutipennis^ Mr. C. E. Hellmayr has found to 

 be a distinct species of an entirely different genus.^ He considers it a 

 member of the genus Caprimulgus^ but the characters he gives in his 

 text and figures show that it without doubt belongs to Mr. Robert 

 Ridgway's new genus Nyctipolus^ and should therefore stand as 

 Nyctipolus hirundinaceus (Spix). 



Specimens examined. — Thirty-one specimens have been seen, from 

 the following localities : 



Brazil. — Bahia; Anjos. 



British Guiana. — Aunai (June 7, 1890; May 14 and 20, 1890). 



Ccflomhia. — Rio San Juan Oscuro (June, 1898). 



Ecuador. — Guayaquil. 



1 Tabl. Planch. Enlum. d'Hist. Nat., 17S3, p. 46. 

 a Planch. Enlum. d'Hist. Nat., No. 732 



s Hist. Nat. des Oiseaux [ed. Montbeillard], vol. 12, 1780, p. 264; orig. ed., vol. 6, 

 1779, p. 547. 



* Novit. Zool., vol. 9, 1902, p. 90. 



5 Syst. Nat,, vol. 1, pt. 2, 17S9, p. 1031. 



* Spix, Avium Spec. Nov. Eras., vol. 2, 1825, p. 2, pi. 3, fig. 1 (Solimoens Rivor, Brazil). 

 '' See Hellmayr, Abhandl. Math.-Phys. Klasse Konigl. Bayer. Akad. Wiss., vol. 22, 1906, 



p. 636. 



^Nyctipolus Ridgway, Proc. Biol. Soc. Wash,, vol. 25, May 4, 1912, p. 98 (type, Capri- 

 mulgus nigrescens Cabanis). 



