RULERS OF THE ANCIENT SEAS 37 



the meantime, the canon of St. Peter's, shrewdly sus- 

 pecting the reason why such peculiar favor was shown to 

 his residence, removed the specimen and concealed it in 

 a vault; but, when the city was taken, the French 

 authorities compelled him to give up his ill-gotten prize, 

 which was immediately transmitted to the Jardin des 

 Plantes, at Paris, where it still forms one of the most 

 interesting objects in that magnificent collection." 

 And there it remains to this day. 



The seas that rolled over western Kansas were the 

 headquarters of the Mosasaurs, and hundreds aye, 

 thousands of specimens have been taken from the 

 chalk bluffs of that region, some of them in such a fine 

 state of preservation that we are not only well ac- 

 quainted with their internal structure, but with their 

 outward appearance as well. They were essentially 

 swimming lizards great, over-grown, and distant rela- 

 tives of the Monitors of Africa and Asia, especially 

 adapted to a roving, predatory life by their powerful 

 tails and paddle-shaped feet. Their cup-and-ball 

 vertebrae indicate great flexibility of the body, their 

 sharp teeth denote ability to capture slippery prey, and 

 the structure of the lower jaw shows that they probably 

 ate in a hurry and swallowed their food entire, or bolted 

 it in great chunks. The jaws of all reptiles are made up 

 of a number of pieces, but these are usually so spliced 

 together that each half of the jaw is one inflexible, or 

 nearly inflexible, mass of bone. In snakes, which swal- 

 low their prey entire, the difficulty of swallowing 

 animals greater in diameter than themselves is sur- 

 mounted by having the two halves of the lower jaw 

 loosely joined at the free ends, so that these may spread 

 wide apart and thus increase the gape of the mouth. 

 This is also helped by the manner in which the jaw is 

 joined to the head. The pelican solves the problem by 



