COLYMBUS. 5 
Genus COLYMBUS Linnaus. (Page 4, pl. L, figs. 2, 3.) 
Species. 
a’, Wing 5.00 inches or more. 
b. Bill about as long as the head. Wing more than 6.00 inches. (Subgenus 
Colymbus.) 
c'. Feathers of lower parts pure white to the extreme base. Wuptial 
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.? 
c’. 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@, 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 Bopp. Red-necked Grebe.* 
@, Length 18.00-20.50; wing 7.30-8.10 (7.65) ; culmen 1.65-2.40 (2.02). 
Eggs 2-5, 2.281.387. Hab. North America, including Green- 
land, breeding far northward ; eastern Asia. 
2. C, holbcellii (Rztnu.). Holbell’s Grebe. 
b. Bill much shorter thanhead. Wing not more than 6.00 inches. (Subgenus 
Dytes Kaur.) 
c, Bill compressed (deeper than wide) at base. WVuptial 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.....ccccsscceeeee ove 3. C. auritus Linn. Horned Grebe. 
c. 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 Colymbue eristatus Linn., 8.N. ed. 10, 1758, 135. 
2 Colymbue grisegena Bopp., Tabl. P. E. 1783, 55. 
