THE JURASSIC PERIOD. 



87 



tail near its extremity for the support of a remarkable caudal fin, in 

 the long snout, set with teeth adapted to seize and hold slipping prey, 



Fig. 362. — A Jurassic spookfish or chimseroid, Squaloruja polyspondyla, one-fourth 

 natural size; from the Lower Lias, Dorsetshire. (Restored by A. Smith Wood- 

 ward.) 



but not to masticate it, in the protection of the eye by bony plates, 

 and, interestingly enough, as it would appear from cumulative evidence, 

 in the development of a viviparous habit that freed them from the 

 necessity of returning to land to deposit their eggs, as do the sea-going 

 turtles and crocodiles. 



The ichthyosaurs became not a little divergent in form, habit and 

 food, and, in the latter part of the period, developed forms (Ophthal- 

 mosaurus, Baptanodon) in which the teeth had been greatly reduced 

 in size; some indeed were for a long time supposed to have been 

 quite toothless. That their food consisted in part of invertebrates 

 is evident from the occurrence of the remains of such animals mingled 



Fig. 363. — A Jurassic forerunner of the modern Amia, Eugnathus athostomus, about 

 one-seventh natural size, from the Lower Lias, Dorsetshire. (A. Smith Woodward.) 



with the fossil contents of the stomach, and it is not unreasonable to 

 suppose their food was largely formed of soft -bodied animals, per- 



