226 



A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



Family ANATIMI. 

 Characters see under Order Anseres. 



Key to genera of Family Anatid^e. 

 Bill more or less wide and depressed and with 

 lamellae not directed backwards ... 2 



1 j Bill narrow, compressed rather than depressed, 

 without lamellae, but with sharp teeth, directed 

 backwards Mergus 



2 | Lores bare Cygnus 



( Lores feathered 3 



I Hind-toe broadly lobed, outer toe almost like 



o! inner 9 



Hind-toe narrowly lobed, outer toe (and especially 



I claw) weaker than middle toe ... 4 



( No metallic or striking colours on wing . . 5 



*•( With metallic or otherwise striking colours on 



C wing 6 



5 j Bill entirely black Branta 



\ Bill never entirely black Anser 



( Upper mandible strongly concave, "nail" re- 

 r. 1 curved over lower mandible, forming a hook . . Tadorna 

 j Upper mandible only slightly concave, nail hot 



' recurved 7 



( Lesser upper wing-coverts white or buff .... Casarca 

 ' \ Lesser upper wing-coverts not white or buff . 8 

 / Upper mandible widened in front like spoon, 



^ » lamellae very fine and long Spatula 



i Upper mandible not perceptibly widened in front, 



\ lamellae shorter and coarser Anas 



q ( Inner primaries partly white or whitish . .10 

 \ Inner primaries brown or blackish . . .11 

 r Bill uniform red or reddish, teeth of upper mandible 



■. r, \ prominent Netta 



1 Bill not uniform reddish, teeth of upper mandible 



( not prominent Nyroca 



Feathering on sides of upper mandible protruding 



in a point to under nostril Somateria 



Feathering on sides of upper mandible not protrud- 

 ing in point to under nostril . . . .12 

 Plumage black or brown, never barred or sharply 



spotted Oidemia 



12 < Plumage not black, if brown partially barred or 



sharply spotted 13 



Feathering at base of upper mandible forming al- 

 most straight line, scarcely interrupted by angle 

 at base of culmen, edge of upper mandible much 



curved Clangula 



Line of feathering at base of upper mandible sharply 

 interrupted by angle at base of culmen, edge of 

 upper mandible almost straight or slightly 



curved 14 



/ Nail of bill small, occupying less than half width of 



, . \ tip of bill Bucephala 



\ Nail of bill wide, occupying whole tip or at least 

 \ more than half width of bill at tip . .15 



, j./ Length of bill under 30 mm Histrionicus 



\ Length of bill over 30 mm Polyeticta 



