INTRODUCTION. 11 



their shafts^ for a certain space towards tlieir ends, 

 entirely destitute of webs on either side j the webs 

 suddenly appearing again only at the top, giving the 

 feather the appearance of a spoon or battledore. 



Slender Tails are generally of moderate length, 

 the feathers being slender throughout, and some- 

 times so abruptly truncated, that their extremities 

 appear to be cut off. 



In Forked Tails the two outer feathers are by far 

 the longest ; the inner ones gradually shortening 

 until the gradation terminates in the central pair. 



In Lyre-shaped Tajls the gradation in the length 

 of the feathers is precisely similar to that in a simply 

 forked tail, but they are curved outwards, so as to 

 resemble in some sort the frame of an ancient lyre. 



Boat-shaped Tails are still more extraordinary; 

 their sides, when expanded, are bent up like the 

 sides of a boat, so as to leave the central part hollow 

 and very concave. This appearance is generally lost 

 in preserved specimens. 



Compressed or Erect Tails are well exemplified 

 in that of the barn-door cock. 



Lastly, Fasciculated or Plumed Tails are those 

 in which the feathers seem to have no regular or de- 

 terminate arrangement, but form bunches of plumes, 

 like that of the Ostrich. 



The hinder limb or Leg of a bird is composed 

 of, — 1. the tibia, generally but erroneously called 

 the thigh; 2. the tarsus, or shank, usually deno- 

 minated the leg; and 3. the toes or digits. Of 

 these last, one, which when present is usually turned 

 backward, or in opposition to the rest, is distin- 

 guished as the hallux. The toes are all of them 

 terminated by claws, variable in their size and shape, 

 and of great importance in the classification of 

 different races. 



The Tarsus by which name we shall designate the 

 shank, is either feathered, as in many of the birds of 

 prey (Fig. 7), or naked, as in the generality of birds. 



A Naked tarsus is protected by Scales {scutel- 



