2 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



I Cutting-edges of bill smooth or festooned, but not lamellated or sharply 



3 I serrated .4 



Cutting-edges of bill lamellated or strongly serrated 20 



Wigeon (Anas penelope), to show lamellated cutting-edges of bill. 



/ Legs inserted near vent, far behind middle of body 

 I Legs inserted about middle of body ..... 



. 5 

 . 6 



f Hind toe present Colymbi (Grebes and Divers) 



* Hind toe absent Alcce (Auks) 



A. Great Crested- Grebe (Colyrribut crittatus). 



B. Red-throated Diver (Gavia stellata). 



C. Black Guillemot (Oriagrytte). 



Anterior toes not or only incompletely 

 webbed 7 



Anterior toes fully webbed : 



Lari (Terns, Gulls, and Skuas). 



Black-headed Gull 

 (Larusridibundw) 



