BIRDS OF NORTH AND MIDDLE AMBEIOA. 545 



Adult maZe.— Length (skins), 255-275 (264); wing, 154.5-171.5 

 (161.3); tail, 148-157 (153.1); exposed culmen, 12-13.5 (12.6); tar- 

 sus, 23.5-26 (24.7); middle toe, 20-22 (21.1)." 



Adult female.— Length, (skins), 245-272 (251); wing, 167-169 

 (159.4); tan, 139.5-158.5 (144.8); exposed culmen, 10.5-14 (12,1); 

 tarsus, 23-25.5 (24.2); middle toe, 19-20.5 (19.9).* 



Southwestern and middle-western Mexico, in States of Sinaloa 

 (Mazatlan; Presidio de Mazatldn; Escuinapa), Jalisco (Ixtapa; 

 Plainsof Colima), Colima (ManzaniUo; Colima), Guerrero (Acapulco), 

 and Oaxaca (Santa Efig6nia; Tehu^ntepec; CuicuitMn; Chihuitto; 

 Salina Cruz), and Territory of Tepic (Santiago; Acaponeta); north- 

 western Chiapas (Tonala)?; Mexico (near City of Mexico) ?; Zaca- 

 tecas ? 



Nyctidromus albicollis (not Caprimulgus albicollis Gmelin) La whence, Mem. Boat. 



Soc. N. H., ii, 1874, 291, part (Mazatlan; Plains of Colima); Bull. U. S. Nat. 



Mus., no. 4, 1876, 31 (Santa Efigenia, Oaxaca). — Salvin and Godman, Biol. 



Centr.-Am., Aves, ii, 1894, 393, part (Presidio de Mazatlan; Mazatlan; San 



Bias and Santiago, Tepic; Plains of Colima; Colima; Zacatecas; CMhuitan, 



Santa Efigenia, Tetuantepec, Chimalapa, and Salina Cruz, Oaxaca; Tonald, 



Chiapas?; Acapulco, Guerrero). 

 {1) Nyctidromus guianensia (not Caprimulgus guianensis Gmelin) Sclater, Proc. 



Zool. Soc. Lond., 1864, 176 (near City of Mexico). 

 Nyctidromus albicollis merrilli (not of Sennett) Miller (W. De W.), Bull. Am. 



Mus. N. H., xxi, 1905, 852 (Escuinapa, s. Sinaloa, resident). 

 Nyctidromus albicollis nelsoni Ridgwat, Proc. Biol. Soc. Wash., xxv. May 4, 1912, 



90 (Colima, Colima, s. w. Mexico; coll. U. S. Nat. Mus.). 



NYCTIDROMUS ALBICOLLIS INSDLARIS Nelson. 



TRES UAHIAS CTTI£tO. 



Similar in coloration to the tawny or rufescent phase of N. a. 

 nelsoni but less bright (not so pronouncedly rufescent) " and size 

 decidedly greater. 



Adult maZe.— Length (skins), 280-290 (285); wing, 164.5-177.5 

 (173); tail, 157-167 (164.9); exposed culmen, 12-13.5 (12.7); tarsus, 

 24-26 (25.1); middle toe, 19-20.5 (19.9)."^ 



Adult female.— Length, (skins), 268-285 (274); wing, 161-174 

 (168.9); tail, 149-159 (154.9); exposed culmen, 11.5-13 (12.6); tar- 

 sus, 23-25 (24.3); middle toe, 18.5-20 (19.7). ' 



O' Nine specimens. 

 6 Ten specimens. 



"= The general tone of coloration (which is very uniform in the series examined) is 

 nearly midway between the extreme phases of N. a. nelsoni. 

 ^ Five specimens. 

 « Six specimens. 



3622°— Bull. 50, pt 6—14 35 



