PLATE XXI. 



ODONTOENITHES. 



Skull, Lower Jaw, and Teeth of Ichthtornis dispar. Marsh. 



All Figures twice Natural Size, except 2a and 25. Page. 



Fig. 1. — Skull ; lateral view, seen from the left, restored in part from skull of a Tern, (Sterna 



regia Gambel), --- 120 



bo — Occipital condyle. 



la — Portion of maxillary, inferior view. 



lb — Superior view. 



Fig. 2. — Rig-lit lower jaw; inner view, 123 



t — Teeth in position. 



e — Suture between splenial and angular bones. 



2a — Tooth from lower jaw; lateral view, magnified eight diameters. 



2b — Anterior view, magnified eight diameters. 



Fig. 3. — Right lower jaw ; superior view, showing distinct sockets for the teeth, 123 



a —Socket for second tooth. 



Fig. 4. — Right lower jaw; reversed, showing exterior surface, 123 



