10 BULLETIN" 86, UNITED STATES NATIONAL MUSEUM. 



carolinensis, and ^^Antrostomus " vociferus, have been used, but skins 

 of a considerable number of other American and Old World species 

 have been examined. All comparisons with Oaprimulgm, however, 

 are entirely with Caprimulgus europaeus (see pi. l,fig. 1), the type of 

 Caprimulgus Linnaeus,^ for it is plain that the genus Caprimulgus, 

 even restricted to Old World species, is a very heterogeneous group' 

 and much in need of careful revision, for which the writer has at 

 present neither time nor adequate available material. 



In the first place, Antrostorrms carolinemis (see pi. 2, fig. 1), the 

 type by subsequent designation ^ of the genus Antrostomus Bona- 

 parte,^ and apparently the only member of this group as I now re- 

 strict it, differs greatly from Caprimulgus in both cranial and 

 external characters, and is really more closely related to Nyctidromus 

 than to either Caprimulgus or Setochalcis.'^ Its diagnosis is as 

 follows : 



Genus ANTROSTOMUS Bonaparte. 



Similar to Caprimulgus Linnseus, but interorbital region of 

 frontals narrower; palatines of very different shape, the distance 

 from their posterior border to the posterior ends of the foramina in 

 their middle portion much greater, nearly double, and these openings 

 much smaller; the inflated posterior parts of the palatines them- 

 selves produced on each side considerably farther back than at the 

 median line, thus more drawn to a point, and the postero-external 

 outline of palatines laterally much less convex, in fact almost straight ; 

 vomer broader, and pointed, instead of bluntly rounded, at its anterior 

 end; maxillo-palatines longer and relatively narrower, more strap- 

 shaped, less shoe-shaped or hook-like; the palatal opening between 

 the halves of the premaxillary smaller and more regularly oval; 

 rictal bristles with long and conspicuous lateral filaments; tail more 

 rounded ; and pterylosis different.^ 



All the other American goatsuckers commonly referred to the 

 genus Antrostomus, excluding those recently removed to other genera 

 by Mr. Eobert Ridgway,« agi^ee, so far as I have been able to exam- 

 me them, very closely in external generic characters, but I have seen 

 the slrull of only " Antrostomus " vociferus, from which I have drawn 

 the cranial characters for this group. Since there are external 

 generic differences distinguishing all these species from both Cap- 

 rimulgus and Antrostomus (carolinensis) , and likewise so many and 

 such excellent cranial characters in ''Antrostomus'' vociferus (see 



^Caprimulgus Linn^us, Syst. Nat., ed. 10, vol. 1. 1758, p. 193 (type, by tautonymy. 

 Capnmulgus europaeus Linnseus). ^ ^^ ' ^ auiyuj^my, 



2 Gray, List Gen. Birds, 1S40, p. 7. 



« Bonaparte, Geog. and Comp, List Birds Europe and North Amer.. 1838 d 8 

 * See p. 11. . H. . 



5 Sec Clark, Auk, vol. 18, 1901, pp. 168-169. 



8 Ridgway, Proc. Biol. Soc. Wash., vol. 25, May 4, 1912, pp. 98-99 



