266 



AVES 



CLASS IV 



Super-Order 1. ODONTOLCAE/ 



Birds with teeth implanted in a continuous groove ; mandibular rami united' at 

 the symphysis by ligament only, and with their component bones free from one another. 

 Clavicles free from one another. Basipterygoid processes wanting; pcdatal structure 

 imperfectly known, but the head of the quadrate is single and the vomer is probably 

 paired. Bones of pelvis free posteriorly ; vertebral articulations saddle-shaped. 



The order Hesperornithes contains members of the genus Hesperornis (Figs. 

 362, ,363, 368) and their allies from the Upper Cretaceous of Kansas. So far 



Fig. 3C8. 

 HesiKi-ornis mjalig, Marsh. Upper Cretaceous ; Kansas. Restoration of skeleton, i/s (after Marsli). 



as is known the teeth in the upper mandible were confined to the maxilla, for 



1 Morsh. 0. C Odontornithes : A Monograph on the Extinct Toothed Birds of North America. 

 Washington. 18S0. — Will isf on, S. TI'., Plumage of Hesperornis (Kan. Univ. Quart, vol. V. p. 

 53), 1S96. 



