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

long jaws are beset by teeth, as in this diagram, in which one of the teeth is represented separately. In possessing true teeth, the Hesperornis differs entirely from any existing bird, and in view of the characteristics of this bird we are obliged to modify the definition of the class of birds and reptiles. Before the discovery of a creature such