SMEW OR WHITE NUN. 351 
Merevus AtBetyus, Linn. Syst. Nat. vol. i. p. 209.—Lath. Ind. Ornith. vol. ii. 
p- 831.—Ch. Bonaparte, Synopsis of Birds of United States, p. 398. 
Smew or WuiteE Nun, Mercus Axusettyus, Wils. Amer. Ornith. vol. viii. p. 126, 
pl. 71, fig. 4. Male. 
The Smew, or WuitTeE Nun, Nuttall, Manual, vol. ii. p. 467. 
Adult Male. Plate CCCXLVII. Fig. 1. 
Bill rather shorter than the head, straight, rather slender, a little 
higher than broad at the base, tapering, somewhat cylindrical toward 
the end. Upper mandible with the dorsal outline sloping gently and 
slightly concave to the middle, then straight, at the tip decurved, the 
ridge rather broad and flat at the base, then convex, the sides sloping 
at the base, convex toward the end, the edges serrate beneath, with 
about forty slightly reversed, compressed, tapering, tooth-like lamelle, 
the unguis elliptical, much curved. Nasal groove oblong, sub-basal, 
filled by a soft membrane ; nostrils oblong, submedial, direct, pervious. 
Lower mandible with the angle very narrow and extended to the obo- 
vate, very convex unguis, the sides rounded, with a long groove, the 
edges with about sixty perpendicular sharp lamelle. 
Head of moderate size, oblong, compressed. Neck of moderate 
length. Body full and depressed. Feet placed far behind, extremely 
short ; tibia bare for a quarter of an inch; tarsus extremely short, much 
compressed, anteriorly covered with a series of very small scutella, 
and another row on the lower half externally, the sides reticulate. 
Hind toe very small, with an inferior free membrane; anterior toes 
double the length of the tarsus; the second shorter than the fourth, 
which is nearly as long as the third; all connected by reticulated webs, 
of which the outer is deeply emarginate. Claws short, considerably 
curved, compressed, acute, that of the middle toe with a thin inner edge. 
Plumage full, soft, and blended; feathers of the head and upper 
part of the hind neck very slender, and elongated along the median line 
into a narrow decurved crest; those of the shoulders obovate and 
abrupt, of the rest of the upper parts ovate, of the lower elliptical. 
Wings very short, narrow, curved, and pointed ; primaries narrow, ta- 
pering, the first scarcely longer than the second, the rest rapidly gra- 
duated ; secondaries short, narrow, rounded, the inner tapering to an 
obtuse point. ‘l'ail short, graduated, of sixteen rather narrow, tapering 
feathers. 
Bill dark greyish-blue. Iris bright red. Feet livid blue, claws dusky. 
