PODICIPID.E— THE GREBES. 259 



This genus includes several subgenera (more or less distinct), 

 of which the following are represented in North America: 



A. Bill about as long as the head ; size large (wing more than 6.00 inches). 



1. Colymbus. 



B. Bill decidedly shorter than head; size smaller (wing less than 6.00 inches). 



2. Dytes. Size medium (wing more than 5.00 inches); nuptial plumage with conspicu- 



ous head-tufts or ruffs, as in Colym b us. 

 [3. Podiceps. Size small (wing less than 5.00); nuptial plumage without head-tufts or 

 ruffs. (Not represented in the Illinois fauna.)] 



Subgenus COLYMBUS Linn.eus. 



Colymbus Linn. S. N. ed. 10, i, 1758, 135. Type, by elimination, C. cristatus Linn. 



Subgen. Chab. Neck much shoiter than the body; bill about equal to the head, stout 

 (length of the culmen about three and a half times the depth through the base), the tip blunt, 

 and the outlines more or less convex; tarsus shorter than middle toe with claw. Breeding 

 plumage ornamented by colored tufts or patches about the head, the winter plumage and 

 the young very different. 



Only one species of this subgenus belongs to North America, 

 the occurrence of C. cristatus — which for half a century or more 

 has been included in most works on North American orni- 

 thology, and generally considered a common bird of this coun- 

 try—being so very doubtful that there is not a single reliable 

 record of its having been taken on this continent. For conven- 

 ience of identification, however, in case it should be found in 

 America, its characters are given below. 



1. C. holboellii. Feathers of lower parts white only superficially, the ba«es of the feathers 

 b sing grayish, this often partly exposed and showing as a more or less distinct spotting. 

 Nuptial plumage with top of head black, rest of head ash-gray, bordered above and be- 

 hind by whitish, the neck rusty. 



2. C. cristatus. Feathers of the lower parts pure white to the extreme base. Nuptial plum- 

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

 throat bully white, this passing behind into bright rusty on a very prominent auricu- 

 lar frill, which is tipped with black. Ua\>. Nearly cosmopolitan, but no reliable North 

 American record. 



Colymbus holboellii (Reinh.) 



HOLBCELL'S GREBE. 

 Popular synonyms. American Red-necked (irebo; Cooper's Grebe, 



Podiceps rubricollia "Lath." Bonap. Synop 1828, H7. Bw, EtlCH. F. B.-A. li,1831, ill.— N'ctt. 

 Mail. ii. 1884, 253.— Aud. Orn. Biog. Ul, U}35,617, pi. 298; By nop, 1839,367; B. Am, vii. 

 1844,312, p] 

 Po rubricollia jfnajor Tkmm. \ Bi in. Jap. 1849, pi. 78 i> (nol Colymbus 



ir Bod 

 ceps holboellii Reinh. Vid. Meddel. I . 1861, U [Greenland).— CouBS.Proo, 



: Nat. Sol. Phila. 1882,231, Redqw, Nona, Am. B, 1881, No. 731, 



