720 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



P\_olioplil(t} caendca caeruka Hkllmayr, Novit. Zool., vii, Dec, 1900, 535; Tier- 



reich, 18 Lief., 1903, 20. 

 [Motacilla] cava Gmelin, Syst. Nat., i, pt. 2, 1788, 973 (Louisiana; based on Figuicr 



cendre a gorge cendrce Buffon, Hist. Nat. Ois., v, 319; Grey-iliroated Warbler 



Pennant, Arctic Zool., ii, 411). 

 ItSglvia'] cana Latham, Index Orn., ii, 1790, 543. 



POLIOPTILA CiERULEA OBSCURA Ridgway. 

 WESTERN GNATCATCHER. 



Similar to I\ e. cxndea, but gray of upper parts slio-htl}' duller and 

 and black at ])ase of inner web of outermost rectrix more extended, 

 usually showing l)eyond tip of under tail-coverts. 



Adult male.—l^^\\gt\\ (skins), 103-115 (107.9); win^ 48-51.5 (4!>.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 {^^S))/' 



Adidtftnude.~-luQVLgth{s\ims),iri-lV2 (105.3); wing, 47-51.5 (48.5); 

 tail, 47-54 (50.4); exposed culmen, 9-10.5 (9.1); tarsus, 16.5-18.5 (17.5); 

 middle toe, 8-9 (8.6).* 



Southwestern United States and contiguous parts of northern Mexico, 

 from 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). 



Muscicapa ccerulea (not MotaciUa cxridca Linnpeus) Gambel, Jonrn. Ac. Nat. Sci., 



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

 Culicivora cicrulia Gambei., Proc. Ac. Nat. Sci., Phila., 1847, 156 (California). 



« Seventeen specimens. 



b Eleven specimens. 



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



Locality. 



Wing. 



Tail. 



Ex- 

 posed 

 culmen. 



Middle 

 toe. 



MALES. 



Eight adult males from western Te.xas to .southern Utah, 

 Arizona, etc 



Three adult males from Caf)e 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 



49.2 



50 

 49.6 



48.9 

 50 



47.3 



52.3 

 50.7 



50.7 

 5L5 



,51.5 

 52 



9.9 

 10.5 



10.5 

 10.4 



9.8 

 10 



10 



17.5 

 17.5 



16.2 

 17.5 



17.5 



17 



8.6 



8.5 



8.5 

 8.5 



8.6 



8.5 



