CLASSIFICATION 193 



Structure of the bill and toes. The following classification is simple 

 and though old, will be found of value in the classroom. 



I. Sternum smooth; wings rudimentary. 



Subclass I, Ratitae. Ostriches. 



II. Sternum keeled; wings well developed. 



Subclass II, Carinatae. Doves. 

 Orders of Carinate Birds. 



1. Wings small and short; diving birds. 



Pygopodes. Penguins, grebes and loons. 



2. Wings long, pointed; anterior toes webbed. 



Longipennes. Petrels, Gulls and Terns, 



3. Feet wholly webbed, including the inner toe. 



Steganopodes. Pelicans and Cormorants. 



4. Bill lamellate, i. e., both mandibles with teethlike projections. 



Lamellirostres. Ducks and Geese. 



5. Waders; legs long, naked above heel, bill usually long and 

 slender Grallatores. Cranes and Snipes. 



6. Land birds ; four toes, three in front, one behind, tibia often 

 spurred Gallinae. Domestic Fowls, Quail and Grouse. 



7. Toes alike, 6; bill horny and convex at tip. 



Columbae. Pigeons and Doves. 



8. Bill curved, hooked and large; feet large; not yoke-toed. 



Raptores. Hawks and Owls. 



9. Feet yoke-toed ; bill stout, strongly hooked .. Psittaci. Parrots. 

 ID. Toes in pairs, two in front, two behind; wings with ten 



primaries Picariae. Woodpeckers. 



II. Perching and singing birds; feet adapted for grasping; hind 



toe opposed to others Passeres. All common birds. 



Following is a synopsis of the Fa^zilies of Order Passeres from 



Jordan's Manual of the Vertebrates. 



Families of Passeres. 



A. Tarsus with its hinder edge rounded; encircled by a single 

 horny envelope divided into scutella anteriorly and on outer side, 

 this sometimes extending all round (though separated by a seam 

 along inner side), but often widely separated on inner side, or 

 behind, or both, the intervening space occupied by granular scales, 

 reticulations, or plain naked skin; musical apparatus imperfect; 

 STU. IN zooL. — 13 



