NATURAL SCIENCES OP PHILADELPHIA. 
233 
Gen. Char. Bill shorter than the head, compressed, exceedingly stout, 
obtuse at the end ; cnlmen straight to the nostrils, then very convex to the 
decurved and acute tip of the upper mandible. Commissure slightly sinuate 
at the base, straight to near the tip, where it is suddenly deflected. Gronys 
regularly convex, Hie angle scarcely appreciable. Upper mandible covered with 
soft skin from the base to the nostrils, between which are two fossae, the an- 
terior shallow and oblong, the posterior triangular and deep, opening into the 
bare loral space; the two separated by an oblique ridge. Nostrils situated 
near the extremity of the anterior fossa. Outer three or four primaries ab- 
ruptly attenuated near the end. Tarsus much abreviated, comparatively 
stout, about three fourths the middle toe and claw. Middle and outer toe 
nearly equal. Lobes of toes broad, connected at base for a greater distance 
than in other genera. 
1. Podilymbus podiceps (Linn.) 
Colymbus podiceps , Linn., 176(5. Podilymbus pod. Lawr., 1858. Podil. 
lineatus , Heerm. , 1854. Colymbus ludovicianus , Gmel., 1788. Podiceps 
ludov. Lath., 1790. Pod. carolinensis, Lath., 1790. Sylbeocyclus carol., 
Bon., 1838. 
Habitat. Continent of North America. 
