THE GENUS CHORDEILES SWAINSON OBERHOLSEE. 87 



CHORDEILES ACUTIPENNIS (Boddaert). 



Caprimulgus acutipennis Boddaert, Tabl. Planch. Eulum. d'Hist. Nat., 1783, 

 p. 46 (Guiana)/ 



Chars, sp. (adult male). — Interorbital region of skull somewhat 

 narrower than in Chordeiles virginianus ; longitudinal ridges on the 

 median portion of frontal bones strongly developed; maxillo-pala- 

 tines relatively rather narrower and more elongated than in Chor- 

 deiles virginianus; vomer rather broader than in Chordeiles virgini- 

 anus; antero-external processes of the palatines decidedly slender, 

 more so than in Chordeiles virginianus ; pterygoids with no decided 

 exterior angle near the anterior end, and the terminal portion ap- 

 proaching the palatine only at the point of articulation; first (outer- 

 most) primary usually shorter than the second; shortest secondary 

 usually reaching or exceeding the tips of the primary coverts ; dis- 

 tance from bend of folded wing to end of shortest secondary nearly 

 always greater than from latter point to end of fourth primary 

 (counting from the outermost) ; tips of most of rectrices usually 

 somewhat squarish; upper surface dark brown or blackish, pro- 

 fusely mottled with white, buff or tawny; tail dark brown, irregu- 

 larly barred, at least on middle feathers, with white, gray, or buff; 

 wing-quills fuscous, the usually four, sometimes five, outer primaries 

 crossed by a large white spot between the tips of the fifth and eighth 

 primaries, the basal portion of primaries and whole of secondaries 

 and primary coverts with conspicuous buff or ochraceous spots or 

 bars; axillars and under wing-coverts buff or ochraceous^ barred 

 with brown ; throat of male white ; jugulum and breast dark brown, 

 vermiculated and spotted with whitish, buffy or ochraceous; rest of 

 lower surface buff or whitish, barred with dark brown. 



Adult female. — Differs from the adult male in much smaller size; 

 smaller, and wholly or largely buff instead of white wing-patch; 

 absence of white subterminal bar on tail ; more whitish or buffy mot- 

 tling on terminal portion of tail, which, in the male, except for the 

 middle pair of rectrices, is usually plain brown; generally more or 

 less buffy throat-patch, which, however, in some individuals is almost 

 as white as in the male; and average rather more ochraceous lower 

 parts. 



First autumn plumage. — ^This is practically the same in both male 

 and female as that of the adults so far as the contour feathers are 

 concerned, and otherwise differs only in having whitish or buffy tips 

 on the primaries, secondaries, and rectrices. These light tips mostly 

 w^ear off before the next molt, but usualh^ persist sufficiently, at least 

 on the shortest secondaries, to serve for the discrimination of year- 

 old birds. 



1 Further synonymy under the various subspecies. 



