ANATIDJE — FULIGULIN^: SEA DUCKS. 699 



in consequence of which the gait is still more awkward and constrained than the " waddle" of 

 ordinary ducks; but swimming powers are enhanced, and diving is facilitated. A large 

 number of the species are exclusively maritime, but this is no more the case with all of them, 

 than is the reverse with the river ducks. These birds feed more upon moUusks and other 

 animal snbstances (not, however, upon fish, like the mergansers) than the river ducks do, and 

 their flesh, as a rule, is coarser, if not entirely too rank to be eaten ; there are, however, signal 

 exceptions to this, as in the case of the canvas-back. The sexes are unlike, as among the 

 Anatince ; and besides the diflference in color, the 9 is often distinguished by the absence or 

 slight development of certain tuberosities of the bill that the $ of several species, as of scoters 

 and eiders, possesses. A large majority of the species inhabit the Northern Hemisphere; there 

 are some forty in all, exhibiting a good deal of diversity in minor details, really requiring 

 recognition of many genera. Among notable exotics, we have the soft -billed Hymenolcemm 

 malacorhynchus of New Zealand, and the short-winged Micropterus cinereus of South America, 

 both related to our genus Camptolcemus ; there are but few others. The genus Erismatura is 

 the type of a small group remarkable for the character of the tail, as desciibed beyond, and 

 sometimes considered as a subfamily apart. Biziura lohata of Australia, ^^^th a fleshy appen- 

 dage under the bill, the African Tlialassornis leuconota, the Nesonetta aticklandica, and several 

 species of Ensmatura and Nomonyx, compose this group. 



Analysis of Genera and Subgenera. 



Tail-feathers rigid, narrow, linear, exposed to their bases by shortness of coverts. 



Nail of bill ordinary Nomonyx 299 



Nail of bill narrow above, overhanging and widened beneath tip of bill Ensmatura 298 



Tail-feathers and their coverts ordinary (central pair very long, however, in Harelda (f). 

 Bill variously gibbous, or appendaged, or feathered beyond nostrils. 



Bill gibbous at base, then broad, depressed, with large fused nail, without frontal processes. 

 Gibbosity of bill superior, circumscribed ; feathers not projected on culmen. \ 



Tail 16-feathered. ,} : Color entirely black (CEdemia) J 



Gibbosity of bill superior, circumscribed; feathers projected on culmen. Tail 14- f . 



feathered, cf : Color black or dark, with white wing-patch (Melanetta) • • / 



Gibbosity lateral as well as superior; feathers projected on culmen. 1 



Tail 14-feathered. ,f : Color black, with white head-patches (Pelionetta) . ' 



Bill gibbous at base, with large frontal processes. \ 



Frontal processes in line with culmen (SoMATERiA proper) I 



Frontal processes bulging out of line with culmen (Erioxetta) f^ . 



Bill not gibbous, but feathered on culmen beyond nostrils (Arctonetta) . . . . / 

 Bill not gibbous, but appendaged with leathery expansion of side of upper mandible, I 



cheeks not bristly (Henicoxetta) / 



Bill not gibbous, but appendaged with a lobe at base of commissure ffistrwnicus 295 



Bill not gibbous, but appendaged with a leathery expansion of side of upper mandible ; cheeks 



bri.stly C'atnptolcemus 294 



Bill ordinary. 



Nail of bill large, fused. Tail (of J") about as long as wing Harelda 293 



Nail of bill narrow, distinct. Tail of ordinary length and shape. 



Bill shorter than head, high at base. Head of ^ pufty or crested, iridescent, with ^ 



white patches; crissum white; colors black and white, in masses ' Clanaula 292 



cf . white spot before eye (Clangtjla proper) ^ 



cf, white patch behind eye (Bucephala) ) 



Bill about as long as head. Head of cf black, red, or brown, without spots ; cris- 

 sum dark 



Bill dusky. Head of <f dusky reddish (Aristonetta) yFuligula 291 



Bill bluish or blackish. Head, of (f black or red. (FuLix) 



Bill red. Head red, crested (European). (Fuligula proper) 



Note. — See further analyses of the subgenera (some of which are of generic value) under heads of (Edemia, 

 Somateria, and Fulignla. 



291. FULI'GULiA. (Lat. fuligula or fulicula, dim. of fulix or fulica, a coot; fuUgo, soot.) 

 Black-head and Red-head Ducks. Scaups and Pochards. Bill ordinary, without 

 special gibbosity or pecuhar outline of feathers at base, only in one species (F. vallisneria) 



