BIRDS OF NORTH AND MIDDLE AMERICA. 559 



[Caprimulgus] yucatanicus Sharpe, Hand-list, ii, 1900, 84. 



Nyctagreus yucatanicus Cole, Bull. Mus. Comp. Zool., 1, 1906, 127 (Chichen-Itza, 

 Yucatan). 



Genus CHORDEILES Swainson. 



Chordeiles Swainson, Fauna Bor.-Am., ii, 1831, 496. (Type Caprimulgus vir- 



ginianus Gmelin.) 

 Chordeilus (emendation) Gray, List Gen. Birds, 1840, 7. 



Chordediles (emendation) Cabanis and Heine, Mus. Hein., iii, Aug., 1860, 86. 

 Chordilcs (emendation) Sundevall, Met. Nat. Av. Dipp. Tent., 1872 86. 

 Microrhynchus (not of Gloger, 1825) Lesson, L'Echo du Monde Sav., 10" an., 



ser. 2, viii, no. 5, July 16, 1843, col. 109. (Type, Caprimulgus exilis Lesson= 



C. pruinosus Tschudi?) 

 Microrhynchos (emendation) Lesson, L'Echo du Monde Sav., IP an., no. 39, 



May 19, 1844, 925; Compl. (Euvr. Buff on, xx, 1847, 259. 

 Ramphaoratus Bonaparte, Rivista Contemporanea, ix, Feb., 1857, 215. (Type, 



Caprimulgus exilis Lesson.) 



Medium-sized Chordeilinse (length about 210-225 mm.), with tail 

 decidedly more than half as long as wing, distinctly emarginate ; tenth 

 (outermost) primary equal to or longer than ninth, and nostrils open 

 (the operculum small). 



Bill very small, the distance from nostril to tip of maxilla equal to 

 about one-fifth the length of commissure, the maxilla with a lateral 

 curved channel. Nostril rather large, opening laterally, more or less 

 triangular or subpyriform, longitudinal. Rictal bristles small and 

 weak, very indistinct. Wing long and pointed, the tenth (outermost) 

 primary longest or equal to ninth, exceeding distal secondaries by 

 decidedly more than half the length of wing. Tail between one-half 

 and three-fifths as long as wing, more or less deeply emarginate, the 

 lateral pair of rectrices longest, the middle pair shortest. Tarsus 

 equal to or very sUghtly longer than middle toe without claw, the 

 upper half (more or less) feathered, except behind; outer toe, without 

 claw, reaching nearly or quite to penultimate articulation of middle 

 toe, the inner toe slightly longer; hallux, with claw, decidedly longer 

 than basal phalanx of middle toe. 



Plumage and coloration. — Plumage in general more compact, with 

 less downy or velvety surface, the primaries and rectrices more rigid 

 than in genera of the Caprimulginas ; no special development of feath- 

 ers on sides of occiput, on chest, nor elsewhere. Upper parts more 

 or less mottled, marbled, or vermiculated (sometimes streaked); adult 

 males with a white area on primaries, and with more or less of white 

 on tail. 



Range. — Temperate North and South America, Bahamas, and 

 Greater Antilles, (About five species.) 



As in the case of Buho virginianus,"' I have followed ^Ir. Oberholser 

 in his treatment of the North and Middle American forms of Clwr- 



a See pages 736-754 of this volume. 



