ODONTOENITHES. 



269 



remains oi Resperornis regalis (fig. 593) prove it to have been 

 a swimming and diving bird, of larger dimensions than any 

 of the aquatic members of the class of Birds with which we 

 are acquainted at the present day. It appears to have stood 



Pig. 592. — Toothed Birds {Odontornithes) of tlie Cretaceous rocks of America, a, Left 

 ower jaw of Ichthyornis dispar, sliglitly enlarged ; &, Left lower jaw of Hes'perornis regalis, 

 reduced to nearly one-foiu'th of the natiu'al size ; c, Cervical vertebra of Ichthyornis dispar, 

 front view, twice the natural size ; c' Side view of the same ; d, Tooth of Hesperornis regalis, 

 enlarged to twice the natural size. (After Marsh.) 



between five and six feet high, and its inability to fly is fully 

 compensated for by the numerous adaptations of its structure 

 to a watery life. Its teeth prove it to have been carnivorous 

 in its habits, and it probably lived upon fishes. Lestornis 

 crassipes of the American Cretaceous is nearly related to 

 Hesperornis ; and the Enaliornis of the Cretaceous of Britain 

 is supposed by Prof. Seeley to be perhaps allied to the same 

 genus, but its jaws are unknown. 



From the next order, the present is readily distinguished 

 by the fact that the vertebroi resemble those of recent birds, the 

 sternum is ivithout a heel, the wings are rudimentary, and the 

 teeth are implanted in a groove in the jaio and not in separate 

 sockets. 



Order II. Odontotorm^. — This order has been founded 

 by Marsh for the reception of two remarkable birds, which 



