266 



AYE& 



1 



CLASS IV 



Super-Order 1. ODONTOLCAE.' 



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

 the Symphysis hy ligament only, and with their component hones free jrom one another. 

 Clavides free from one another. Basipterygoid processes wanting; palatal struäure 

 imperfedly known, but the head of the quadrafe is single and the vomer is probably 

 paired. Bones of pelvis free posteriorly ; vertebral articidations 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. 368. 

 Hesperornis regalü, Marsh. Upper Cretaceous ; Kansas. Restoration of skeleton, Vs (alter Marsh). 



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



1 Marsh, 0. C, Odoutornithes : A Monograph on the Extinct Toothed Birds of North America. 

 Washington, 18S0. — Will iston, S. TF., Plumage of Hesperornis (Kan. Univ. Quart, vol. V. p. 

 53), 189(). 



