276 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



Genus ^CHMOPHORUS Coues. 



I. ^)chmophorus occidentalis (L/AWR.). 



WESTERN GREBE. 



Geographical distribution: Western North America, east to Man- 

 toba and south to Mexico; accidental east of Nebraska. 



Special characters, adult: Top of head and back of neck, sooty 

 black; rest of upper plumage, slaty gray; forehead and lores, ashy 

 white; primaries, dark chocolate, showing white at the bases; neck 

 (except the back) and under parts, glossy white. 



Length, 23 to 29; wing, 7 to 8.40; bill, 2.40 to 3. 



According to Kumlien and Hollister, this western species has been 

 taken in Wisconsin. A specimen was killed on Lake Koshkonong, 

 January 4, 1878, by L. Kumlien, and another in the same locality, 

 October, 1881. (Bull. Wis. Nat. Hist. Soc., 1903, p. 5.) As far as 

 we know it has not as yet been observed in Illinois. 



Genus COLYMBUS Linn. 



2. Colymbus holboellii (REINH.)- 

 HOLBCELL'S GREBE. 



Distr.: North America in general, breeding chiefly north of the 

 United States. 



Adult in summer: Top of head, small crest and back of neck, 

 greenish black, or glossy black; throat and sides of the head, silvery 

 white, or whitish ash; most of neck, rujous brown, shading into silvery 

 white on the lower breast and belly; back, black, some of the feathers 

 with grayish edgings; primaries, chocolate brown, the shafts, black. 



Adult in winter: Above, blackish; crest, nearly or quite absent; 

 front and sides of neck tinged with pale brown; throat, white; under 

 parts, white. Immature birds have the upper parts dull black; the 

 throat and under parts, silvery white, and the neck, grayish (not 

 tinged with brown). 



Length, 18 to 20; wing, 7.35 to 8; bill, 1.75 to 2.30. 



Holboell's Grebe is rare in Illinois and casual in Wisconsin during 

 late fall and early spring, and a few remain in winter. Mr. E. W. 

 Nelson gives it as a "rather uncommon winter resident upon Lake 

 Michigan." (Birds N. E. Illinois, 1876, p. no.) Kumlien and Hol- 

 lister say, "Holboell's Grebe is found sparingly in March and early 

 April on most of the larger inland lakes and rivers, as well as on Lake 

 Michigan, and again from September, but more often from October, 



