232 THE ANATOMY OF VERTEBRATED ANIMALS. 



A. With two joints in the ulnar digit of the manus. 



Ornitkopterus. 



B. "With four joints in the ulnar digit. 



a. The jaws strong, pointed, and toothed to their anterior ex- 



tremities. The tail very short. The metacarpus usually 

 longer than half the length of the antebrachium. 

 IHerodadylus. 



b. The extremities of the jaws produced into toothless beaks> 



probably ensheathed in horn. The tail very long. The meta- 

 carpus shorter than half the length of the antebrachium. 

 a. All the mandibular teeth similar. 

 Hhamphorhynclius. 



h. The posterior teeth for the most part very short. The 

 anterior long, 



DimorpJiodon. 



I am mucli inclined to suspect that the fossil upon which 

 the genus OmitliopUrus has been founded, appertains to a true 

 Bird 



