PROFESSOR HUXLEY'S LECTURES. 



217 



it indeed that, had this skeleton "been found in a museum, I suppose 

 if the head had not been known it would have been placed in the 

 same general group as the divers and grebes of the present day. But 

 this bird differs from all existing birds, and so far resembles reptiles 

 in one important particular that it is provided with teeth. These 



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Fig. 4. Ichthtorkis Dispae. (Marsh.) 



long jaws are beset by teeth, as in this diagram, in which one of the 

 teeth is represented separately. In possessing true teeth, the Hesper- 

 omis differs entirely from any existing bird, and in view of the char- 

 acteristics of this bird we are obliged to modify the definition of the 

 class of birds and reptiles. Before the discovery of a creature such 



