194 EXTINCT MONSTERS 



considerable speed. Like snakes, they were furnished with four 

 rows of formidable teeth on the roof of the mouth, which served 

 admirably for seizing their prey. 



But the most remarkable feature in these creatures was the 

 arrangement for permitting them to swallow their prey whole, 

 in the manner of snakes. Thus each half of the lower jaw was 

 articulated at a point nearly midway between the ear and the 

 chin, so as to greatly widen the space between the jaws, and 

 Professor Cope thinks that the throat must consequently have 

 been loose and baggy. 



Professor Cope, however, in giving the name Pythonomorpha 

 to this ancient group, has pressed his views too far, and dwelt 

 unduly on their supposed relationship with serpents. Other 

 authorities regard them as essentially swimming lizards, with 

 four well-developed paddles ; and this is probably the right view 

 to take of them. 



" If, as appears certain," says the Professor, " the Mosasauroid, 

 discovered by Webb, measures seventy-five feet in length, and 

 the M. maximus, eighty, the Leiodon dyspelor must have been the 

 longest reptile known, and approaches very nearly the extreme 

 of the mammalian growth seen in the whales, though, of course, 

 without their bulk. Such monsters may well excite our surprise, 

 as well as our curiosity, in the inquiry as to their source of food- 

 supply, and the character of those contemporary animals preserved 

 on the same geological horizon." 



According to Dr. S. W. Williston, who has, of late years, dis- 

 covered and described most valuable specimens of Mosasauroid 

 reptiles, Clidastes had a skull less flattened than that shown in 

 some earlier restorations (e.g. in the previous edition of this book) 

 and the digits were curved, as in Platycarpus. Of the former 

 reptile, which was forty feet long, a single specimen was 



