258 BIRDS OP ILLINOIS, 



Family PODICIPID-ffi.— The Grebes. 



Characteks. Swimmers resembling the Loons in the posterior insertion of the legs, 

 but the toes lobate and semipalmate, instead of completely webbed, the claws broa ', flat, 

 and nail-like, instead of normally narrow and curved. Bill variable in shape; nostrils vari- 

 able, but without an overhanging lobo; wings very short and concave, the primaries cov- 

 ered by the secondaries in the closed wing: tail rudimentary, consisting of a mere tuft of 

 downy, loose-webbed feathers, without perfectly formed reotriees; plumage of the lower 

 surface remarkably silky and lustrous, usually white. 



The Grebes are aquatic birds, poorlv adapted for protracted 

 flight, on account of the smallness of their wings, but amous; 

 the most expert of divers. Their nest is a thicli matted plat- 

 form of rushes, sedg-es, etc.. usually floating upon the surface of 

 the water in gras.sy or sedgy ponds or marshes. The eggs are 

 2-5, dull white, bluish white, or very pale bluish green, usually 

 stained more or less (often quite deeply') with light brown, by 

 contact with decomposed vegetable matter. 



The recognized North American genera may be distinguished 

 as follows: 



A. Bill slender, the length of the culmcn much more Ihan twice the depth of the bill at the 



base. 

 [I. .Eclimopliorus. Length of culmen at least five times the greatest depth of the bill; 

 neck nearly as long as the body. (Not represented in the Illinois fauna.)] 



2. Colymbus. Length of culmen less than four times the greatest depth of the bill; 



neck much shorter than the body. 



B. Bill very stout, the length of the cttlmen loss than twice the gi-eatest depth of the bill. 



3. Fodilymbus. 



Genus COLYMBUS Linn.eus. 



Colymbus Linn. S. N. ed. 10, i, 1758, 135; ed. 12, i, 1760, 220. Type, by elimination. Colymbus 



cri.itatiis Linn. 

 Podiceps likin. Ind. Orn. ii. 1790,780 (part; but, type, by elimination and restriction, Colyut- 



lusjluviatilis TUNST.). 

 Dytes Kaup. Sk. Ent. Eur. Thierw. 1820, 4'J. Type, Coliimbuf: conxiUts Gmel..=C'. avritiis 



Linn. 

 Proctoi'us Kaup. I.e. Type, Podiceps nigricolliK Bkebm. 

 Otodytes Keich. Syst. Nat, 1853. p. Ill (same type). 

 Tachybaptus Keichenb. Syst, Av. 1852. p. iii. Type, Colvmh^ts >i> inor 0'!lETj..= C.tlHvMilis 



TuNST. 



Gbn. Chak. Neck much shorter than the body; bill not longer than the head, more or 

 less slender, its depth never more than one third the length of the eulmon; tarsus decidedly 

 shorter than middle toe wiih claw. Nuptial plumage ornamented by colored tufts, ruflfs, or 

 patches about the head, and very different in this respect from the winter plumage. 



