ANATID^ — 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 cS,se with all of them, 
than is the reverse with the river ducks. These birds feed more upon mollusks and other 
animal substances (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 
sliglit 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 Hymenolmmus 
malacorhynchus of New Zealand, and the short-winged Micropterus cinereus of South America, 
both related to our genus CamptolcBmus ; there are but few others. The genus Ei'ismatura is 
the type of a small group remarkable for the character of the tail, as described beyond, and 
sometimes considered as a subfamily apart. Biziura lohata of Australia, with a fieshy appen- 
dage under the bill, the African Thalassornis leuconota, the Nesonetta aucklandica, and several 
species of Erismatura 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 Erismatura 298 
Tail-feathers and their coverts ordinary (central pair very long, however, in Harelda cf ). 
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 IG-feathered. cf : Color entirely black (CEdemia) 
Gibbosity of bill superior, circumscribed; feathers projected on culmen. Tail 14- ( (Edemia 297 
feathered, (f : Color black or dark, with white wing-patch (Melanetta) . . 
Gibbosity lateral as well as superior; feathers projected on culmen. 
Tail 14-feathered. J" : Color black, with white head-patches (Pelionetta) . 
Bill gibbous at base, with large frontal processes. 
Frontal processes in line with culmen (Somateria proper) 
Frontal processes bulging out of line with culmen (Erionetta) 
Bill not gibbous, but feathered on culmen beyond nostrils (Arctonetta) .... 
Bill not gibbous, but appendaged with leathery expansion of side of upper mandible, 
cheeks not bristly (HENicoisrETTA) 
Bill not gibbous, but appendaged with a lobe at base of commissure Histrionicus 295 
Bill not gibbous, but appendaged with a leathery expansion of side of upper mandible ; cheeks 
bristly Camptolcemus 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 cf pufty or crested, iridescent, with ) 
white patches; crissum white; colors black and white, in masses ( Clangula 292 
(f, white spot before eye (Clangula proper) ( 
<f, white patch behind eye (BucEPHALA) ) 
Bill about as long as head. Head of (f black, red, or brown, without spots ; cris- "\ 
sum dark I 
Bill dusky. Head of cf dusky reddish (Aristonetta) \ Fuligula 291 
Bill bluish or blackish. Head of cf black or red. (FuLix) i 
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 CEdemia, 
Somateria, and Fuligula. 
FULI'GULA. (Lat. fuligula or fulicula, dim. of fulix or fulica, a coot; fuligo, 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) 
Somateria 296 
