ODONTOLCA K. 



459 



united. The teeth are found all along the lower jaw, butjare confined 

 to the maxilla in the upper jaw. The palatal structure is not fully 

 known, but there are no basipterygoid processes ; the head of the 

 quadrate is single. The vertebral centra are saddle-shaped, and the 



Fir;. 251,Hesperornis regalis, 



U. Cretaceous, Kansas (from S. Woodward, after 

 Marsh). 



bones of the pelvis are free posteriorly. There is no pygostyle Ena- 

 liornis from the Cambridge Greensand, and Baptornis from the North 

 American Cretaceous are probably here. 



The so-called Stereor n it hes include a number of large extinct land birds, 

 the skeletons of which have been found in the lower Tertiaries of South 



* Andrews, Ibis, 1890, p. 1. Lydekker, Ibis, 1893, p. 40, and Dictionary 

 of Birds, p. 904. 



