720 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



P{olioptila'] caerulea caerulea Hellmayr, Novit. Zool., vii, Dec, 1900, 535; Tier- 



reich, 18 Lief., 1903, 20. 

 [Motacilla] cana Gmelin, Syst. Nat., i, pt. 2, 1788, 973 (Louisiana; haaedonFiguier 



cendre a gorge cendne Buffon, Hist. Nat. Ois., v, 319; Grey-throated Warbler 



Pennant, Arctic Zool., ii, 411). 

 [Sylvial cana Latham, Index Orn., ii, 1790, 543. 



POLIOPTILA CjERULEA OBSCURA Ridgway. 

 WESTERN GNATCATCHER. 



Similar to P. c. caerulea, but gray of upper parts slightly duller and 

 and black at base of inner web of outermost rectrix more extended, 

 usually showing beyond tip of under tail-coverts. 



Adult mafe.— Length (skins), 103-115 (107.9); wing, 48-51.5 (49.9); 

 tail, 49.5-55.5 (51.7); exposed culmen, 9.5-11 (10.2); tarsus, 16-18 

 (17.3); middle toe, 8.5-9 (8.6).« 



.A<?i«^i!/e7rtffl^e.— Length (skins), 97-112 (105.3); wing, 47-61.5 (48.5); 

 tail, 47-54 (50.4); exposed culmen, 9-10.5 (9.1); tarsus, 16.5-18.6 (17.5); 

 middle toe, 8-9 (8.6).* 



Southwestern United States and contiguous parts of northern Mexico, 

 fi'om western Texas (west of Pecos River) to California; northward 

 to Colorado (regularly to El Paso County, accidentally to Denver), 

 southern Utah (Beaverdam; Santa Clara Valley), southern Nevada 

 (Mount Magruder), and interior of northern California (Napa, Tehama, 

 Shasta, Siskiyou, and Placer counties) ; southward to Cape St. Lucas 

 (in winter only ^) and through Mexican States of Chihuahua, Sonora, 

 and Sinaloa (near Mazatlan; Culiacan) to Colima (Plains of Colima, 

 January). 



Mtiseicapa ccendea (not Motacilla cxrulea Linnfeus) Gambel, Journ. Ac. Nat. Si-i., 



Phila., i, 1847, 38 (California). 

 Culicivora cierulia Gambel, Proc. Ac. Nat. Sci., Pliila., 1847, 156 (California). 



« Seventeen specimens. 



>> Eleven specimens. 



Specimens from different geographic areas average, respectively, as follows: 



Locality. 



Middle 

 toe. 



MALES. 



Eight adult males from western Texas to southern Utah, 

 Arizona, etc - . - . 



Three adult males from Cape district, Lower California 



Two adult males from southern California (San Diego 

 County) 



Three adult males from northern California 



FEMALES. 



six adult females from New Mexico and Arizona 



One adult female from Cape district, Lower California 



Three adult females from southern California and northern 

 Lower California 



8.6 

 S.5 



8.5 

 8.5 



