46 BULLETIN 86, UNITED STATES NATIONAL MUSEUM. 



CHORDEILES VIRGINIANUS HESPERIS Grinnell. 



Chordeiles virginianus hesperis Geinnell, Condor, vol. 7, November 22, 

 1905, p. 170 (Bear Lake, San Bernardino Mountains, California). 



Chars, subsp. — Similar to Chordeiles virginianus virginianus^ but 

 male with upper surface lighter, the ground color more brownish, 

 the light markings more numerous, particularly on back, scapulars, 

 tertials, and superior wing-coverts; the posterior lower parts less 

 washed with buffy, and the dark bars averaging narrower. 



Measurements. — Male: Total length (in flesh), 220.7-260.3 (aver- 

 age, 240.5) mm. ; ^ extent of wing, 568.2-609.6 (588.9).^ 



Female : Weight, 4 ounces avoirdupois.^ 



Male: 3 Wing, 183-211 (average, 200) mm.; tail, 107-120 (112.9) ; 

 exposed culmen, 6.0-8.0 (6.9) ; tarsus, 13.8-15.2 (14.3) ; middle toe, 

 14-15.5 (14.7). 



Female:* Wing, 187-203 (194.9) mm.; tail, 105-119 (112.2); ex- 

 posed culmen, 6.1-8.0 (7.0) ; tarsus, 13-15.2 (14.5) ; middle toe, 

 14.2-16 (15.3). 



Type-locality. — Bear Lake, 6,700 feet altitude, San Bernardino 

 Mountains, southern California. 



Geographical distribution. — Extreme western United States and 

 southern edge of southwestern Canada; south in winter, probably 

 to South America. Breeds in the Upper Austral, Transition, and 

 Canadian zones, north to Indian Head and Maple Creek, southern 

 Saskatchewan; Many Island Lake, near Walsh, southeastern Al- 

 berta; Trail, southeastern British Columbia; and Fort Steilacoom, 

 Puget Sound, northwestern Washington; west to Aberdeen, central 

 western Washington; Astoria, Newport, and Glendale, western 

 Oregon; Humboldt Bay and Ukiah, northwestern California; Au- 

 burn in Placer County, central California; and the Kern River 

 Lakes and Santa Barbara, southwestern California; south to Ven- 

 turia County, and to the South Fork of the Santa Ana River, and Fish 

 Creek in the San Bernardino Mountains, southwestern California; 

 east to Sugarloaf Peak in the San Bernardino Mountains, south- 

 western California; Furnace Creek in Death Valley, southeastern 

 California ; Mount Magruder, southwestern Nevada ; Eureka, central 

 Nevada; Fairfield, north central Utah; Promontory, central north- 

 ern Utah; Blackfoot, southeastern Idaho; Upper Geyser Basin, in 

 Yellowstone National Park, northwestern Wyoming; Bozeman, 

 Great Falls, and the Bear Paw Mountains, central Montana; and 

 Indian Head, central southern Saskatchewan. Migrates southward 

 through Kansas, Colorado, Arizona, New Mexico, Texas, Mexico, and 

 Nicaragua. Winters probably in South America. 



1 Two specimens. 



- One specimen. 



^ Ten specimens, from California, Oregon, and Montana. 



* Ten specimens, from California, Oregon, and Idaho. 



