208 



THE WORLD OF LIFE 



CHAP. 



B 



as shown in the drawings here reproduced (Fig. 62 A, B). 

 They were also remarkable for their very large and highly 

 organised eyes, which, with the lengthened jaws and closely 

 set sharp teeth, indicate a perfect adaptation for capturing 

 the fishes which the seas of that age no doubt produced in 



the same abundance and 

 almost as great variety 

 as our own. These crea- 

 tures also varied much 

 in size and shape, one 

 from the Lower Lias of 

 Warwickshire being 22 

 feet long, but detached 

 vertebras sometimes in- 

 dicate a much larger 

 size. In the older Tri- 

 assic beds smaller species 

 are found which were less 

 completely aquatic ; and 

 these seem to show 

 an affinity to Amphibia 

 rather than to reptiles, 

 indicating that the two 

 aquatic orders may have 

 had independent origins. 

 Still later, in the 

 Cretaceous formation, 

 there were other aquatic 

 reptiles quite distinct 

 from all the preceding, 

 and more allied to our 

 living lizards, having 

 well - formed swimming 

 feet, but snake-like or fish-like bodies. These serve to 

 indicate how completely the reptiles of the Secondary epoch 

 occupied the place now filled by the Mammalia, somewhat 

 similar forms adapted for aquatic life being again and again 

 developed, just as the Mammalia subsequently developed 

 into otters, seals, manatees, porpoises, and whales. 



o 00 



Fig. 62. 

 Right Fore (A) and Hind (B) Paddles 



of Ichthyosaurus intermedws. 



From Lower Lias of Lyme Regis. One-third 



nat. size. (B.M. Guide.) 



I 



