166 STRUCTURAL AND SYSTEMATIC ZOOLOGY 



bill are of proportionate length,- and the tail short. 

 They feed on small animals, and, with a few exceptions, 



FIG. 144. Heron (Ardea). 



frequent the banks of rivers. In flying, their legs are 

 stretched out behind, while in most other birds they 

 are folded under the body. 



6. Anseres have a heavy body, moderate wings, short 

 tail, flattened bill, covered by a soft skin, with ridges 

 along the edges. Diet more commonly vegetarian than 

 animal. The majority inhabit fresh water as the 

 ducks, geese, and swans. "'-'. !~ 



7. Accipitres, including the diurnal birds of prey. 

 They have a strongly hooked beak with a waxy mem- 

 brane (cere) at the base of the upper mandible, three 

 toes in front and one behind. The toes are armed with 

 long, strong, crooked talons; the legs are robust, the 

 tarsus and toes usually without feathers being covered 

 by scales ; and the wings are of considerable size, 



