BIRDS OF NORTH AND MIDDLE AMERICA. 523 



tail-coverts nearly immaculate ; under wing-coverts blackish brown or 

 dusky transversely spotted with dull ochraceous, especially toward 

 edge of wing; inner webs of primaries uniform blackish brown, in the 

 closed wmg, but with a few small concealed spots of ochraceous or 

 ochraceous-buff ; bill blackish brown, darker terminally; feet blackish 

 brown, the tarsi paler; length (skins), 241-245 (243); wing, 166.5- 

 167.5 (167); tail, 122.5-135 (128.7); exposed cuhnen, 14.5-16 (15.2); 

 tarsus, 17-18 (17.5); middle toe, 16.5-17 (16.7).« 



Adult female.^ — Much paler and more grayish than the adult male, 

 and closely resembling the adult female oi A. v. macromystax, from 

 which the chief difference consists in the greatly reduced size of the 

 tawny-ochraceous spots or bars on inner webs of primaries, slightly 

 darker general tone of coloration of upper parts (especially the middle 

 rectrices), and paler buff of collar across lower throat, length (skins), 

 232-243 (237.5) ; whig, 159-162 (160.5) ; tail, 113.5-123 (118.2) ; exposed 

 cuhnen, 14-15.5 (14.7); tarsus, 17.5-18 (17.7); middle toe, 17-17.5 

 (17.2).« 



Youn^.— Apparently distinguishable from the young of A. v. macro- 

 mystax only by the absence of distinct transverse spots on inner webs 

 of primaries. 



Extreme southern Mexico, in State of Chiapas (Valley of Comitan ; 

 Ocozucuantla; Teopisca) and Guatemala (Lake Atitlan; Tecpam). 



(?) Antrostomus ? Owen, Ibis, 18G1, G4 (Santa Barbara, Vera Paz, Guate- 

 mala; descr." eggs). 



(?) [Caprimulgus vociferiis] subsp. a. Caprimulgus macromystax Hartert, Cat. 

 Birds Brit. Mus., xvi, 1892, 570, part (Coban, Santa Barbara, and Volcan de 

 Fuego, Guatemala). 



Antrostovius chiapensis Nelson, Auk, x\'ii, July, 1900, 261 (Valley of Comitan, 

 Cliiapas; coll. U. S. Nat. Mus.).— Dearborn, Pub. 125, Field Mus. N. H., 

 1907, 94 (Lake Atitlan and Tecpam, Guatemala, above 5,000 feet). 



ANTROSTOMUS OAXACvE Nelson. 



OAXACA WHIPPOORWILL. 



Very sunilar to A. vociferus macromystax, but shghtly darker above, 

 with black spots on pileum smaller, more triangular, with less Ught 

 mottling on scapulars, and breast spotted instead of vermiculated. 



Adult female.'' — Pileum brownish gray, mmutely and indistinctly 

 freckled and vermiculated wuth darker, each feather (except on 

 lateral portions) with a terminal spot of black, these spots regularly 

 triangular on forehead and crown, more elongated and irregular on 



« Two specimens. 



^ Perhaps of this species, but possibly another form. If really the same, I know 

 of no other instance of such marked sexual difference in coloration among birds of 

 this family. 



c The adult male is as yet unknown. 



