1912] Swarth: Birds and Mammals from Vancouver Island 71 



Tahsis Canal between July 24 and August 1. During the fall 

 migration it was met with on but two occasions, single birds being 

 seen at Errington on September 2 and 10, respectively. 



Sixteen specimens were preserved (nos. 16409-16424), all 

 adults in breeding plumage. 



Geothlypis trichas occidentalis Brewster 

 Western Yellowthroat 



Common in the swampy meadows at Errington and at Beaver 

 Creek. Not met with elsewhere, though at Nootka Sound at 

 least, there was plenty of ground suited to the species. Young 

 out of the nest were taken at Beaver Creek on May 30, and 

 subsequently during June. On June 14 Miss Kellogg found a 

 nest with four eggs (no. 1076). It was in a clump of grass at 

 the edge of a small stream flowing through an open meadow, and 

 was built of grass blades, lined with finer stalks of grass and one 

 or two horse hairs. 



Yellowthroats were abundant at Errington early in Sep- 

 tember, evidently migrating; by the end of the month they had 

 nearly all disappeared. 



Thirty-seven specimens were collected (nos. 16425-16461), 

 twenty-one summer adults, seven juvenals, and seven immatures 

 and two adults in fresh winter plumage. 



This series of yellowthroats does not coincide with the ac- 

 cepted descriptions of Geothlypis t. arizela, the form supposed 

 to inhabit the region. In fact, none of the series of western 

 yellowthroats in this Museum (except G. t. sinuosa) lend them- 

 selves to the divisions of the species as generally accepted. 



The latest authority (A. O. U. Cheek-List, 1910, pp. 322. 323) 

 gives the breeding range of G. t. occidentalis as follows: "Breeds 

 .... from central Alberta, southern Saskatchewan, and South 

 Dakota to southeastern California, northeastern Lower Califor- 

 nia, Chihuahua, and western Texas"; of G. t. arizela: "Breeds 

 .... from southern British Columbia to southern California 

 and east to Fort Klamath, Oregon." 



The differences between occidentalis and arizela, according to 

 the original describer of the latter (Oberholser, 1899, p. 256), 

 and according to Ridgway (1902, p. 670), are briefly as follows: 



