CO LY MB US. 



GENUS COLYMBUS LINNAEUS. (Page 4, pi. I., figs. 2, 3.) 



Species. 



a 1 . Wing 5.00 inches or more. 



b l . B1H about as long as the head. "Wing more than 6.00 inches. (Subgenus 



Colymbus.') 



c 1 . Feathers of lower parts pure white to the extreme base. Nuptial 

 plumage : Throat and chin buffy white, passing posteriorly into rich 

 ferruginous on the very prominent auricular frill, which is tipped 

 with black ; top of head and elongated tufts on each side of occiput 

 glossy black. Length 22.00-24.00; wing 6.80-7.75; culmen 1.75- 

 2.30. Hab. Nearly cosmopolitan, but no authentic record for any 

 portion of America. 



C. cristatus LINN. Crested Grebe. 1 



c 2 . Feathers of lower parts white only superficially, the concealed portion 

 being distinctly grayish. Nuptial plumage : Top of head dull black, 

 somewhat glossy ; rest of head ash-gray, bordered above and poste- 

 riorly by whitish ; neck rufous. 



d 1 . Length about 17.50 ; wing 6.45-7.00 (6.63) ; culmen 1.50-1.55 (1.53). 

 Hab. Northern portions of eastern hemisphere. 



C. grisegena BoDD. Red-necked Grebe.* 



d\ Length 18.00-20.50 ; wing 7.30-8.10 (7.65) ; culmen 1.65-2.40 (2.02). 

 Eggs 2-5, 2.23 X 1-37. Hab. North America, including Green- 

 land, breeding far northward ; eastern Asia. 



2. C. holbcellii (EEINH.). Holbcell's Grebe. 

 b*. Bill much shorter than head. Wing not more than 6.00 inches. (Subgenus 



Dytes KAUP.) 



c 1 .. Bill compressed (deeper than wide) at base. Nuptial plumage : Lower 

 neck and chest rufous; sides of occiput with a very full dense 

 tuft of soft, blended, ochraceous feathers. Downy young: Whole 

 top of head dusky ; sides of head whitish with two stripes and 

 several irregular spots of dusky ; a dusky streak on each side of 

 throat ; upper parts plain dusky grayish. Length 12.50-15.25 ; wing 

 about 5.75. Eggs 2-7, 1.78 X 1-20. Hab. Northern portion of 

 northern hemisphere, breeding in America chiefly north of the 



United States 3. C. auritus LINN. Horned Grebe. 



c 2 . Bill depressed (wider than deep) at base. Nuptial plumage : Head, neck, 

 and chest black ; sides of head, behind eyes, with a tuft-like or 

 somewhat fan-shaped loose patch of slender ochraceous feathers. 

 Downy young : Top of head dusky, with several white markings, the 

 middle of the crown with a small naked, reddish space ; no dusky 



1 Colymbus cristatus LINN., S.N. ed. 10, 1758, 135. 



2 Colymbus grisegena BODD., Tabl. P. E. 1783, 55. 



