340 BULLETIN 50, TJNITED STATES NATIONAL MUSEUM. 



Adult female.— L,ength (skins), 302-310.5 (306.6); wing, 172.5-174.5 

 (173.5); tail, 150.6-153.5 (152); exposed culmen, 26.5-27 (26.9); depth 

 of bill at nostrils, 10.5; tarsus, 41-43.5 (42.5); middle toe, 22-26 (24).« 



Southwestern portion of Mexican plateau, in States of Jalisco (La 

 Laguna; Jacala; San Sebastian; Sierra Nevada) and Colima (Sierra 

 Madre). 



Aphelocoma sieberi colimie Nelson, Auk, xvi, Jan., 1899, 27 (Jacala, Jalisco, s. w. 

 Mexico; coll. U. S. Nat. Mus.). 



APHELOCOMA SIEBERII POTOSINA Nelson. 



SAN LTJIS POTOSI JAY. 



Similar to A. v. sieberi i, but decidedly smaller, bill larger, and colora- 

 tion of upper parts paler, the blue of a light azure or almost cerulean 

 hue, and the posterior under parts more extensively white (entire 

 flanks and lower abdomen white, or nearly so). 



Adult m.ale.—L,ength (skins), 284.5-308 (299); wing, 160-172 (169); 

 tail, 137-151 (146); exposed culmen, 28-29.5 (29); depth of bill at 

 nostrils, 10-11 (10.6); tarsus, 42.6-44.5 (43.5); middle toe, 24-25.5 

 (24.5).* 



Adult fe/nale.—hength (skins), 282-302 (293); wing, 154-160.5 

 (157.5); tail, 132-141 (136); exposed culmen, 26.5-29 (27.5); depth of 

 bill at nostrils, 10.5; tarsus, 41-42 (41.6); middle toe, 22.5-24 (23).« 



Northeastern portion of Mexican plateau, in States of Hidalgo (El 

 Chico, Tulancingo) San Luis Potosi (mountains near Jesus Maria; 

 Villar), southern Tamaulipas (Miquihuana), and southern Coahuila 

 (Carneros); Guanajuato? 



('!) Cyanocitta sordida (not Oarrulas sordidus Swainson?) Duges, La Naturaleza, 



i, 1869, 139 (Guanajuato). 

 Aphelocoma sieberi potosina Nelson, Auk, xvi, Jan., 1899, 27 (mountains near 



Jesus Maria, San Luis Potosi, Mexico; coll. U. S. Nat. Mus.). 



APHELOCOMA SIEBERII ARIZON.^; (Ridgway). 

 ARIZOITA JAY, 



Similar in coloration to A. s. luollweberi^ but much larger; about the 

 same size as A. s. potosina, but very much paler and duller colored. 



Adult mafe.— Length (skins), 291-318.5 (303.5); wing, 168.5-173 

 (167); tail, 143.5-164.5 (149); exposed culmen, 27.5-32.6 (30.5); depth 

 of bill at nostrils, 10-11 (10.5); tarsus, 41.5^4.6 (42.5); middle toe, 

 22.5-24(23.6).'^ 



Adidt female.— Tuength (skins), 282-306 (297.5); wing, 152.6-167.5 

 (162.5); tail, 136-151 (146.5); exposed culmen, 26.6-30 (28); depth of 

 bill at nostrils, 9.9-10.7 (10.4); tarsus, 40.6-44 (42.6); middle toe, 

 21.8-22.6 (22.1).'- 



o Three specimens. !> Four specimens. " Five specimens. 



