18 TADORNA. SHIELDUCK. 



verse, thin, elevated lamellae, which are much larger and more 

 widely set toward the end. Tongue fleshy, deeply grooved 

 above, with lateral series of bristles, and a thin broadly 

 rounded tip, (Esophagus of moderate width. Stomach a 

 very large, transversely elliptical gizzard, placed obliquely, 

 with very large muscles, thick rugous epithelium, and thick- 

 ened grinding plates. Intestine very long, and of moderate 

 width ; coeca very long. 



Trachea of nearly unifonu width, but a little enlarged 

 within the furcular space, then narrowed ; the lower larynx 

 with two unequal irregularly roundish extremely thin bony 

 sacs, of which that on the left side is much larger. Bronchi 

 of moderate size. 



Nostrils oblong, moderate, in the lower and fore part of 

 the membrane. Legs short ; tibia bare for a very short space ; 

 tarsus short, compressed, with very small anterior scutella ; 

 hind toe very small, elevated, with a lobiform membrane ; 

 inner toe much shorter than the outer, Avhich is nearly equal 

 to the third, the latter rather longer than the tarsus ; all 

 scutellate above ; interdigital membranes full. Claws small, 

 compressed, little arched, rather blunt, that of the middle toe 

 expanded internally. 



Plumage dense, soft, and blended ; feathers of the head 

 and upper-neck short and silky, of the other parts large ; 

 scapulars large, oblong, rounded. Wings rather long, broad, 

 pointed ; the second quill longest, the first little shorter ; 

 inner secondaries elongated, oblong. Tail moderate, nearly 

 even, of fourteen weak, rounded feathers. 



The males differ from the females only in being larger. 

 They continue with the female and young. The food con- 

 sists of vegetable substances and shell-fish. The eggs are 

 numerous, ovate, glossy, and white or cream-coloured. The 

 species of this genus, being of a large size, and rather bulky 

 pi'oportions, bear a considerable resemblance to some of the 

 Geese, especially to those of the genus Chenalopex, and 

 might with almost equal propriety be referred to that family, 

 with which they further agree in the similarity of plumage of 

 the two sexes, whereas in the other Anatina^, the males differ 

 from the females in this respect. 



