i68 



THE CHAIN OF IJFE. 



the same relation to the other members of the class Rcptilia 

 which the Whales and Porpoises bear to the ordinary ([uadru- 

 peds. Some of these animals are believed to have been fifty 

 or sixty feet in length, thus rivalling the Whales, while others 



Fig. 142a.— Head of /V/o.vrt//;7/i-. Jurassic. Mucli reduced. 



were of smaller dimensions, like the Porpoises and Dolphin?. 

 Some, like the Ichthyosaurus and Pliosaurus (Fig. 142^), were 

 strongly built and powerful swimmers, and able to destroy the 

 largest fishes, while others, like Pksiosaurus, had the body 

 short and compact, the head small, and the neck long and 



,^^^^ 







Fig. i^2lj.—V:iM\^oi J'lesiosattrus OxoHiensis. Jurassic- After Pliiliips. One-tenth 



natural size. 



flexible, and probably preyed on small animals near the 

 borders of the waters. Catalogues of British fossils alone 

 include about thirty species of Enaleosaurs, which haunted 

 the coasts of Mesozoic Europe, a wonderful fact, when we 

 consider the absence of these creatures from the modern seas, 

 and the probability that only a fraction of the species are yet 

 known to us. 



