CXXIV 
INTRODUCTION. 
Bill deep reddish flesh-colour, with a tolerably well-developed knob and broad triangular space between 
tbe bill and the eye. Breadth of the black space, including the part bebind tbe knob, 2 inches. Eye 
dark brown. 
Feet olive-grey, even to the joints ; interdigital membranes darker. Length of true tarsi 4f inches ; 
bare space above the joint li inch ; middle toe and nail 6i inches ; breadth of the foot 6i inches. 
Having disposed of the Geese and Swans, we naturally turn to the true grass-feeding Ducks, after which 
will be noticed those species which almost exclusively feed under the surface of the water — the 
Fuligulinm &c. 
Subfamily ANATINdE. 
Genus Tadorxa. 
An Old-World group of five or six species. 
327. Tadorna vulpanser ........... Vol. V. PI. XI. 
Sheldrake. ' 
A stationary species, breeding in the holes of warrens and sandy wastes by the sea-side. 
Genus Casarca. 
328. Casarca rutila ............ Vol. V. PI. XII. 
Ruddy Sheldrake. 
An occasional and very rare visitant. Among other places, builds in rocks on the borders of tbe 
Mediterranean. 
Genus Mareca. 
A genus of which our common Widgeon is the type, and of which an allied species is found in North 
America and another in Chili. 
329. Mareca penelope ........... Vol. V. PI. XIII. 
Widgeon, 
A migrant which is plentiful in winter, and sometimes, but not very regularly, stays to breed in England 
and Scotland. 
330. Mareca Americana. 
American Widgeon. 
An occasional visitant to England. It is not figured. 
