492 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



gg. Tail double-forked or double-emarginate, the middle rectricea 

 much louger than second, third, aud fourth pairs, sometimes 



nearly as long as outer pair Hydropsalis (extralimital) .« 



ff. Tail without any elongated rectrices. 

 g. Longest primaries exceeding distal secondaries by decidedly more 

 than half the length of wing ; remiges and rectrices relatively nar- 

 rower, the former straight terminally; tenth (outermost) primary 

 nearly equal to eighth, sometimes longer. 



Caprimulgus (extralimital). & 

 qg. Longest primaries exceeding distal secondaries by decidedly less 

 than half the length of wing; remiges and rectrices relatively 

 broader, the former more or less bowed or incurved terminally; 

 tenth (outermost) primary much shorter than eighth, or else 

 {Antiurus) equal to or longer than ninth. 

 h. Tenth (outermost) primary equal to or longer than ninth; sides of 

 head black margined above by a buff superciliary stripe. 



Antiurus (extralimital) .c 



hh. Tenth (outermost) primary decidedly shorter than ninth, usually 



shorter than eighth; sides of head not black, and without a 



buff superciliary stripe. 



i. Tail truncate or emarginate. 



j. Tail distinctly emarginate, in the male nearly as long as 



wing; sexes conspicuously different in coloration, the 



male with lateral rectrices mostly (sometimes wholly) 



white Stenopsis (p. 497) . 



a Hydropsalis Wagler, Isis, 1832, 1222. (Type, Caprimulgus furcifcr Vieillot or 

 C. manurus Vieillot=i7. furcifer or ?) — Hydropsalia (emendation) Gray, List Gen. 

 Birds, 1840, 8. — Hydropsallis (emendation?) Keichenbach, Av. Sys. Nat., 1850, pi. 

 xc. — Psalurus Swainson, Classif. Birds, ii, 1837, 338. (Type, Caprimulgus torquatus 

 Gmelin.) — Diplopsalis Sclater, Proc. Zool. Soc. Lond., 1866, 141. (Type, Hydropsalis 

 climacocercus Tschudi.) — {'f)Tetroura Lesson, L'Echo du Monde Savant, 10« ann., no. 

 5, July 16, viii, 1843, col. 109. (Type, Caprimulgus enicurv^ Vieillot = unidentified 

 species.) — Tetrura (emendation) Lesson, L'Echo du Monde Savant, 11« ann., no. 39, 

 May, 1844, 925; Compl. Buff., xx, 1847, 259. 



British Guiana to upper Amazon Valley, Bolivia, northern Argentina, Paraguay, 

 and Brazil. (Four species, of which only H. torquata and H. schomburghi have been 

 examined in this connection.) 



b Caprimulgus Linnaeus, Syst. Nat., ed. 10, i, 1758, 193. (Type, as fixed by Gray, 

 1840, C. europxus Linnaeus.) — Nyctichelidon Rennie, in Montague's Orn. Diet., 1831, 

 335. (Type, Caprimulgus europxus Linnagus.) — Phalsenivora Blyth, Analyst, v, no. 

 xvii, Oct., 1836, 79; in White's Nat. Hist. Selborne, 1836, 49, 72, footnote. (New 

 name for Caprimulgus Linngeus.) 



Eastern Hemisphere. (Many species?) 



In Sharpe's Hand-list of the Genera and Species of Birds (ii, 1900, 85-88), forty- 

 eight Old World species are referred to the genus Caprimulgus. How many of these 

 are really congeneric with C. europxus, or whether some of them may not be referable 

 to the American genus Antrostomus, has nothing to do with the question of whether 

 the two genera are distinct or not. The characters given above are taken entirely 

 from C. europxus and C. ruficollis, both of which are unquestionably different in 

 several structural characters from any American species of the family. 



c Antiurus Ridgway, Proc. Biol. Soc. Wash., xxv, May 4, 1912, 98. (Type, xS'ie- 

 nopsismaculicaudus Ij^iwxQncG.) (^Aincoc, different; oupa, tail.) 



