101 



AYTHYA. POCHARD. 



The Pochards, of which the most characteristic species 

 are the celebrated Canvas-back of America, and the common 

 E-ed-headed Pochard of that continent as well as of Europe, 

 differ from the Scaup-Ducks in no other essential respect 

 than in having the bill narrower and more elongated, and 

 the membrane of the hind toe of less breadth. They may 

 be described as having the body very large, full, and de- 

 pressed ; the neck moderate ; the head rather large, oblong, 

 compressed, and rounded above. 



Bill as long as the head, higher than broad at the base, 

 becoming depressed toward the end, of nearly equal breadth 

 throughout ; the upper mandible with the basal lateral 

 sinuses short and wide, the upper sinus rather narrow, the 

 frontal angles acute, the dorsal line declinate for half its 

 length, then direct to the unguis, which is small, oblong, 

 flattened, and decurved ; the ridge broad and flat at the 

 base, gradually narrowed, convex toward the end, the sides 

 at the base nearly erect, toward the end gradually more 

 spreading and convex ; the edges soft, marginate, concealing 

 the ends of the numerous, little elevated lamellae ; the nasal 

 sinus rather small, oblong, sub-basal ; lower mandible with 

 the intercrural space very long, rather narrow, the crura 

 slender, with their lower outline slightly recurvate, the 

 outer lamellae small, the unguis obovate, rather small, and 

 little convex. 



Mouth rather narrow ; anterior palate broadly concave, 

 with a median prominent line, on which are a few tubercles ; 

 the lateral lamellae slender, little elevated ; those of the 

 lower mandible about double the number. Tongue fleshy, 

 with a deep median groove, papillate at the base, lamelloso- 

 filamentous on the margins, with the tip thin and somewhat 



