52 BULLETIN 86, UNITED STATES NATIONAL MUSEUM. 



CHORDEILES VIRGINIANUS SENNETTI Coues. 



iChordiles popetue] Sennetti Coues, Auk, vol. 5, January, 1888, p. 37 (50 

 miles west of Pembina [sic], North Dakota; and Wharton County, 

 Texas). 



Chars, subsp. — Resembling Chordeileis virginianus h£speris, but 

 upper surface of male lighter and more grayish, i. e., the dark brown 

 ground color lighter and more grayish, the light markings finer, more 

 numerous, and paler, more grayish or whitish (less ochraceous) ; 

 general tone of lower surface lighter, the dark anterior portions more 

 grayish, the bars on posterior portion narrower, sometimes inter- 

 rupted. 



Measurements. — Male: Total length (in flesh), 212.6-247.6 (aver- 

 age, 231.6) mm.; 1 extent of wing, 412.8-590.6 (541).^ 



Female: "Weight, 2 ounces 4 drams to 3 ounces 3 drams avoirdu- 

 pois ^ (average, 2 ounces 13.3 drams). 



Male: 3 Wing, 186-213 (average, 198.3) mm.; tail, 101.5-112.5 

 (109.1) ; exposed culmen, 6.0-7.2 (6.9) ; tarsus, 13.5-15.8 (14.6) ; 

 middle toe, 13.9-16 (15.3). 



Female:* Wing, 175-201 (189.5) mm.; tail, 102.5-115 (108); ex- 

 posed culmen, 6.0-7.5 (6.5) ; tarsus, 13.8-15.3 (14.7) ; middle toe, 

 14^16 (14.9). 



Type-locality. — Fifty miles west of the Pembina Mountains, in cen- 

 tral northern North Dakota. 



Geographical distribution. — Central northern United States, prob- 

 ably south in winter to South America ; breeds in the Upper Austral 

 and Transition zones, north to Pembina, to Towner County, and old 

 Fort Union, northern North Dakota ; and Strater, northeastern Mon- 

 tana ; west to Strater, Darnall's Ranch in Dawson County, and Fort 

 Keogh, eastern Montana ; and Uva, southeastern Wyoming ; south to 

 Uva, southeastern Wyoming; Rosebud, central southern South Da- 

 kota ; Thomas County and Antelope County, north central Nebraska ; 

 Sioux City and Dickinson County, northwestern Iowa ; east to Dick- 

 inson County, northwestern Iowa ; Madison, southwestern Minnesota ; 

 and Pembina, northeastern North Dakota. Migrates through Kansas 

 and eastern Colorado, and probably Central America. Winters prob- 

 ably in South America. 



Remarks. — This is easily seen to be one of the palest races, and is 

 characterized, particularly in the male, by the grayish cast of light 

 and dark colors both above and below, as compared with the other 

 forms. The broad light streaks on the nape, especially, are very light 

 buff or even whitish, and the upper surface of the wings has much 



1 Four specimens. 



2 Three specimens. 



3 Ten specimens, from South Dakota, North Dakota, Minnesota, and Montana. 

 * Ten specimens, from South Dakota and North Dakota. 



