PODICIPID^ — THE GREBES — COLYMBUS, 



425 



Eggs of this species from Shoal Lake, in British America, vary from 2.15 inches 

 to 2.60 in their length, and from 1.45 to 1.50 in tlieir breadth. They are unspotted, 

 and in all essential respects resemble the eggs of all the members of the entire 

 genus. 



Genus COLYMBUS, Linx^eus. 



Colymhus, LiNN. S. N. ed. 10, I. 1758, 135; ed. 12, I. 1766, 220 (type, by elimination, Cohjmhus 



cristatas, Linn. ).i 

 Podicci^, Lath. Ind. Orn. IL 1790, 780 ({jart ; but, type, by elimination and restriction, Colymbus 



fluviatilis, TuNsT. ). 



Char. Neck much shorter 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 out- 

 lines more or less convex ; tarsus shorter than middle toe with claw. Breeding plumage orna- 

 mented by colored tufts or patches about the head, the whiter plumage and the young very 

 different. 



A^ 



C. cristatm. 



Only one species of this genus, as here restricted, belongs to North America, the occurrence of 

 C. cristatus — which for half a century or more has been included in most works on North AiMorican 

 ornithology, and generally considered a connnon bird of this country —being so very doubtful that 

 there is not a single reliable record of its having been taken on tins continent. For convenience 

 of identification, however, in case it should l)e found in America, the characters of this species are 

 given along with those of C. Holbcellii and the European representative of the latter, C. grisegena. 



1. C. Holboellii. Wing, 7. 3(V8. 10 inches (average, 7.65); culmen, 1.65-2.40 (2.02); depth 

 of bill at base, .52-.60 (.57); tarsus, 2.25-2.60 (2.53); outer toe, 2.50-3.05 (2.76). No 



1 Notwithstanding the extreme di.slike we have to this harsh transfer of the name Cohjmhus from the 

 Loons to the Grebes, we unfortunately can see no help for it. Sundevall has clearly shown (Met. Av, 

 Nat. 1872, p. xxix) that it .should never have been retained for the former, and most other authorities are 

 pretty well agn^ed as to the incorrectness of its use in that connection. It is a ease in which the facts 

 are clear, and the rules of procedure so explicit that tlicrc is no alternative if we would be consistent in 

 our efforts to assist toward reaching a fixed or stable nomenclature. 

 VOL. II. — 54 



