342 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



usually distinctly gray (deep ash gray to bluish gray, rarely grayish 

 blue); under parts paler, more extensively white posteriorly. 



Adult ;««fe.— Length (skins), 274.5-294.5 (284); wing, 148-164.6 

 (158); tail, 128.5-144 (135.5); exposed culmen, 24.5-27.5 (27); depth of 

 bill at nostrils, 9.5-10.5 (10); tarsus, 39-42 (40.5); middle toe, 20.5- 

 24 (28).« 



Adult female.— L,%VLg\k (skins), 272-288.5 (281); wing, 150.5-155 

 (154.5); tail, 129-136 (132.5); exposed culmen, 24^27(25); depth of bill 

 at nostrils, 8.5-10.5 (9.6); tarsus, 37-41 (39); middle toe, 19.5-24.5 (22).* 



Northwestern and central portions of Mexican plateau, in States of 

 western San Luis Potosi (Villar), Zacatecas (Valparaiso, Plateado, Monte 

 Escobedo, Sierra Madre), northern Jalisco (Bolanos, Florencio, Colat- 

 lan), Durango (El Salto; La Providencia), southwestern Chihuahua 

 (Jesus Maria, Colonia Garcia, etc.), and eastern Sinaloa (Sierra de 

 Choix), and Territory of Tepic (Santa Teresa). 



Aphelocoma wollweberi" Kaup, Journ. fiir Orn., ii, no. 12, Suppl., Nov., 1854, p. 



Iv, footnote (Zacatecas, Mexico; coll. Wolhveber). 

 Aphelocoma gracilis Miller, Auk, xiii, Jan., 1896, 34 (Sierra Bolanog, Jalisco, 



Mexico; coll. G. S. Miller, jr.). 



APHELOCOMA SIEBERII COTTCHI (Baird). 

 COUCH'S JAY. 



Similar to A. s. potosina in coloration, but much smaller and bill 

 more slender; similar also to A. «. loollweberi, but still smaller, with 

 larger bill. 



Adult viale.— Length (skins), 261.5-289.5 (273.5);* wing, 144.5- 

 152.5 (147.5);* tail, 124.6-137 (129);* exposed culmen, 25-28 (27);« 

 depth of bill at base, 9.5-12 (10.6);* tarsus, 39-43.6 (41);* middle toe, 

 21.5-25.5 (23.6).* 



Adult feinale.— Length (skin), 261.5-269 (266.5);* wing, 142-162.5 

 (147.5); exposed culmen, 25-26.5 (25.5); depth of bill at base, 10-11.5 

 (10.5); tarsus, 39-40.5 (39.5); middle toe, 22-23.5 (22.6).'' 



Southern Nuevo Leon (Guajuco,^ Monterey, Parras, etc.) to south- 

 western Texas (Chisos Mountains). 



''Seven specimens. 



6 Six specimens. 



«"Ich unterscheide Aphelocoma Wollweberi, die zwischen ultramarina und sieberi 

 steht. Sie ist weniger intensiv blau, mit rothlich grauem Riicken. Wangen und 

 Ohrfedern dunkler blau. Ziigel schwarzlich. Schwanz schwach gegabelt, in dem die 

 mittleren Schwanzfedern kiirzer als die seitlichen sind. In geeignetem Licht zeigen 

 die Schwanzfedern Spuren von Binden. 



"Wollweberi, Lange 10 Par.", Schnabel 13"', Fliigel 5" 5"', Schwanz 4" 5"-4" 9'". 



" VUramimna, Lange 11 Par.", Schnabel 13"', Fliigel 5|*, Schwanz 4" 5"-4" 9'". 



"Sieberi, Lange 13 Par.", Schnabel 13'", Fliigel 6" 10'", Schwanz 6|". 



"Zaccatekas, durch Hrn. Wollweber in hiesiger Sammlung." 



t^Two specimens. 



«Guajuco is about 18 miles southeast of Monterey, and is the type locality as 

 shown by the original labels of the type specimens. 



