232 THE ANATOMY OF VERTEBRATED ANIMALS. 



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



B. With four joints in the ulnar digit. 



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



tremities. The tail very short. The metacarpus usually 

 longer than half the length of the antebrachium. 

 Pkrodaciyliis, 



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. 



Ehamphorhynchus. 



b. The posterior teeth for the most part very short. Tho 



anterior long. 



Dimorphodon. 



I am much inclined to suspect that the fossil upon which 

 the genus Ornithopterus has been founded, appertains to a true 

 Bird. 



