PALMIPEDES. 261 



B- Bill narrow, with the margrin covered with reflected 

 teeth, and the upper mandible hooked at the end. 



210. Mergus. Goosander. Hind toe furnished with a 

 fin. Nostrils near the middle of the bill. M. Merganiicr, 

 serrator and albellus. 



Margin of the bill destitute of teeth. 



A. Wings short. This character renders flying difficult in 

 all cases, and in some impracticable. The legs are placed 

 farther back than in other birds. They constitute the 

 Brachypteres of C u v i e ii . 



Wings destitute of quill feathers. In walking, the tarsus, 

 which is broad behind, is applied to the ground. 



211. Aptenodytes. Penguin. Palate and tongue 

 beset with reflected prickles. 



Wings with quill feathers. 



Bill much compressed and obliquely furrowed. No hind 

 toe. This includes the genus Alca of Li\. 



212. Alca. Awk. Base of the bill feathered. A.impen- 

 nis and torda. The A. pica is merely the razorbill in its win- 

 ter dress, and also its immature state. I have had an op- 

 portunity of observing, that the black feathers, on the side 

 of the head and throat, in the irnpennis and tarda, during 

 the summer season, change to white in winter. 



213. Fratercula. Base of the bill and part of the 

 cheeks covered with coloured skin. Alca aretica^ Lin. 



Bill more or less conical and compressed. 



Membrane of the toes lobbed. 



214. PoDicEPS. Grebe. Bill straight, pointed. Mid- 

 dle claw flattened. P. cristatus. 



Membrane of the toes entire. 



