

BIEDS WITH TEETH. 59 



assumption, had not other and more complete evidence 

 been obtained. Professor Marsh, discovered two fossil 

 birds in the cretaceous shale of Kansas, which had 

 well-developed teeth in both jaws. Of one of these 

 birds the Ichthyornu Dispar " the teeth were quite 

 numerous/' Marsh wrote in Silliman's Journal for 

 October, 1872, " and implanted in distinct sockets. 

 They were small, compressed, and pointed, and all of 

 those preserved are similar. Those in the lower jaw 

 number about twenty in each ramus" (that is, on. 

 each side) ' ' and are all more or less inclined back- 

 wards. The series extend over the entire margin of 

 the dentary" (or tooth-bearing) "bone, the front 

 teeth being very near the extremity. The maxillary 

 teeth " (those in the upper jaw, that is) cc appear to 

 have been equally numerous, and essentially the same 

 as those in the mandible. The skull was of moderate 

 size, and the eyes were placed well forward. The 



lower jaws are long and slender The jaws were 



apparently not encased in a horny sheath." The 

 shoulder-blades and the bones of the wings and legs 

 were all .of the true bird-like type. The breast-bone 

 had a prominent keel. The wings were large in pro- 

 portion to the legs. The wing-bones, corresponding 

 to the hand in man, were united as in ordinary birds. 

 The bones of the hinder extremities resembled those 

 in swimming birds. The bird was about as large as 

 a pigeon. The species was carnivorous, and probably 

 aquatic. Professor Marsh called the other form dis- 

 covered by him Apatornis celer. 



