97 
FAMILY XL.— MERGING. MERGANSERS. 
Bill rather long, straight, rather slender but strong, tapering, higher than 
broad at the base, nearly cylindrical toward the end ; upper mandible with 
the dorsal outline sloping gently to the middle, then straight, along the 
unguis suddenly decurved ; the ridge broad and flattened at the base, then 
convex, the sides sloping, toward the end convex, the edges serrate internally 
with oblique dentiform lamellae, the unguis oblong, much curved, abruptly 
rounded at the end ; nasal groove elongated, covered by the soft skin of the 
bill ; lower mandible with the angle very narrow and extended to the unguis, 
which is obovate,_ the sides nearly erect, with a long narrow groove, the 
edges internally serrate, the unguis convex, thick-edged. Head rather large, 
compressed, oblong ; neck of moderate length ; body full, depressed, rather 
elongated. Feet placed far behind, stout ; tibia bare for a short space ; tarsus 
very short, compressed, anteriorly covered with small scutella, and another 
series on the lower half externally. Hind toe very small, with an inferior 
free membrane ; anterior toes half as long again as the tarsus, second shorter 
than the fourth, which is almost as long as the third, all scutellate, and con- 
nected by anteriorly concave webs. Claws rather small, moderately arched, 
compressed, acute. Plumage moderately full, dense, soft, glossy, blended 
beneath. Wings of moderate breadth, convex, acute ; inner secondaries 
elongated and tapering. Tail short, much rounded, of more than twelve 
feathers. Upper mandible with an internal series of small papillae or laminae 
on each side, besides those on the margin. Tongue long, fleshy, emarginate 
and papillate at the base, tapering, with a double row of slender reversed 
papillae along the upper surface, and two lateral series of filaments on each 
side, the tip lacerated ; oesophagus very wide, of nearly uniform diameter ; 
stomach a strong gizzard of moderate or small size, with the lateral muscles 
thick ; the epithelium dense and longitudinally rugous ; intestine long, rather 
narrow ; cceca rather long ; cloaca globular. Trachea with one or two 
extensive dilatations, besides the enormously developed tympanum at the 
bifurcation ; no inferior laryngeal muscles. Nest on the ground, or in hollow 
trees. Eggs numerous. 
Genus I.— MERGUS, Linn. MERGANSER. 
Character as above. 
Yol. YIL— 13 
