AN INTRODUCTION TO THE BIRD. 229 
rear toe and claw are as long as the inner toe and its 
claw. Then it is one of the Passrrzs. 
(46) If leg round in rear and hind claw never ex- 
ceedingly long and straight, it is one of the CLama- 
TORES. 
(47) If the shank is sharp in the rear, or if round 
with the rear claw long and straight, it is one of the 
OscINEs. 

The highest type of passerine foot, showing 
unbroken rear side plate, forming the sharp 
edge of oscine shank. 
