204 



MERGANSER. GOOSANDER, 



Bill about the length of the head, nearly straight or 

 slightly reareuate, rather stout and of greater height than 

 breadth at the base, tapering to the middle, beyond which it 

 is slender and cylindrical ; upper mandible Avith its dorsal 

 outline declinate for half its length, then direct and straight 

 to the oblongo-elliptical convex unguis, which is abruptly 

 decurved and rounded at the end, the lateral sinuses shortly 

 rounded, the upper rather acute, the ridge broad at the base, 

 gradually narrowed, the nasal sinus oblong, sub-basal, the 

 edges marginate, serrate, with dentiform compressed, tapering 

 lamellae ; lower mandible Avith the intercrural space very 

 long, narrow, toward the end linear, the crura slender, 

 slightly reareuate at the base, laterally grooved, their erect 

 edges with dentiform laniellse, the unguis obovate and con- 

 vex ; the gape-line nearly straight. 



The mouth narrow, but dilatable ; palate flat ; roof of 

 upper mandible nearly flat, narrow, with a medial prominent 

 line, a series of slight oblique lamellae on each side, sepa- 

 rated by a groove from the marginal series. Tongue slender, 

 fleshy, papillate or bristly above and on the edges, with the 

 tip narrow and lacerated. (Esophagus very wide in its 

 whole length, more dilated within the thorax ; the proven- 

 tricular belt continuous. Stomach roundish, of moderate 

 size, very muscular, with a dense rugous epithelium. Intes- 

 tine long, rather wide anteriorly, narrowed toward the coeca, 

 which are moderate, narrow at the base, cylindrical, obtuse ; 

 rectum with a large globular dilatation. 



Trachea in the female simple and uniform ; in the male 

 with one or two dilatations, and an enormously large laby- 

 rinth at the lower end, partly bony and partly membranous. 



Nostrils oblong, pervious, in the fore part of the nasal 



