29 



ANAS. DUCK. 



Our common Wild Duck, or Mallard, the original of the 

 domestic varieties, may be considered as the type or charac- 

 teristic representative of this genus, of which the species are 

 not numerous. The body is large, ovato-olliptical, about the 

 same height and breadth ; the neck rather long ; the head 

 oblong, compressed, of moderate size. 



Bill about the length of the head, higher than broad at 

 the base, gradually depressed, becoming a little broader 

 toward the end, and very slightly re-arcuate ; upper man- 

 dible with the lateral sinuses very broad, the upper semi- 

 circular, the frontal angles short and pointed, the dorsal line 

 sloping to beyond the nostrils, then nearly straight, the ridge 

 flattened and gradually narrowed ; the unguis obovate, de- 

 curved, with the end sharp-edged and rounded, the sides 

 convex, at the base nearly erect, the lamellse with their 

 outer ends thin and scarcely apparent externally ; the nasal 

 sinus moderate, somewhat elliptical, close to the ridge ; 

 lower mandible slightly re-arcuate, with the intercrural space 

 very long, narroAv, and bare ; the crura slender, with their 

 sides convex, gradually sloping more outwards ; the unguis 

 obovato-triangular, little convex, broadly rounded. 



Mouth rather narrow ; anterior palate concave, with a 

 medial ridge, and on each side a series of transverse thin, 

 elevated lamellae ; external lamellae of the lower mandible 

 slender, but distinct. Tongue fleshy, grooved above, with 

 the sides parallel and furnished with a double series of fila- 

 ments, the base with numerous conical papillae, the tip thin 

 and rounded ; oesophagus of moderate width, considerably 

 enlarged at the lower part of the neck. Stomach a very 

 large, oblique, transversely elliptical gizzard, with extremely 

 large lateral muscles, strong tendons, dense, rugous epithe- 



