382 
Synopsis of the Birds 
SUBGENUS I. RHYNCHASPIS. 
'Rhynchaspis , Leach. Steph .* Spatula , Boie. Les Sou- 
chets, Cuv . 
Bill long, without fleshy protuberance ; upper mandible 
serni-cylindric, broad and sub-orbicular at the end, nail small, 
much incurved ; lamelliform teeth very long, fine and slender.. 
Head wholly feathered. 
Female differing greatly from the male. 
Feed chiefly on small aquatic animals, which they obtain 
by sifting the mud between their teeth. Bill very sensible, 
as appears by the desiccation of the nervous apparatus. 
322. Anas clypeata, L. Mirror green, margined above with 
white, below black ; wing-coverts light bluish. 
Male brown ; head and neck green; belly chesnut. 
Female and young wholly brownish, varied with yellowish 
and blackish. 
Shoveller , Anas clypeata , Wils . Am. Orn. viii. p. 65. pi* 67° 
fig- 1 
Inhabits the north of both continents, extending its periodi- 
cal migrations far to the south : not uncommon during winter 
throughout the United States and Mexico. 
SUBGENUS II. ANAS. 
Anas , Dafila , Mareca , Querquedula, Steph. 
Bill moderate, subequal in breadth throughout, without 
fleshy protuberance ; teeth small, comparatively coarse. 
Head wholly feathered. 
* Stephens, however, in his genus Rhynchaspis , includes species belong- 
ing to our genus Fuligula , as well as to our Anas. According to his sys- 
tem they even belong to different stirpes , and the common character being 
one of analogy simply, he must form a new genus, for which names enough 
may be found. Spatula might be applied to the present, Rhynchaspis to 
the latter. 
