308 VERTEBRATE AXIMALS. 



is the type. In Ichthyornis, as in Hesperornis, tlie jaws are fur- 

 nished with numerous cunical teeth, but those are sunk in dis- 

 tinct sockets. The wings are well developed, and the bird must 

 have possessed considerable powers of flight. The sternum has a 

 keel, and the metacarpal hones are anchylosed with one another. 

 Lastly, there is the extraordinary character that the bodies of the 

 vertebrce were biconcare, and in this respect resemble the vertebrae 

 of most fishes and of many Amphibians and Reptiles. The size of 

 Ichthi/ornis dispar, the only known species of the genus, seems to 

 have been about equal to that of a Pigeon. 



