32 



Ichthyosauria. 



Table-cases, 

 Nos.4and5. 



Order yiL ICHTHYOSAURIA (FISH-LIZARDS). 

 These great marine carnivorous reptiles had very short 

 neckg ^ Woodcut, Fig. 43), probably not visible at all ex- 



FIG. 38. Left lateral aspect of the skull of Ichthyosaurus communis (Conybeare) ; from 

 the Lower Lias, Lyme Kegis, Dorset (about A nat. size). The body was entirely devoid 

 of any hard exo-skeleton. 



Fie. 39. Left lateral and anterior aspects of the centrum of an early posterior dorsal 

 vertebra of Ichthyosaurus trigonus (Owen); Kimmeridge Clay, Stanton. a, upper, 

 b, lower costal tubercle. 



FIG. 40. The centrum of an anterior dorsal vertebra ,of Ichthyosaurus cntheciodon (Hulke); 

 Kimmeridge Clay, Wilts. A, section: B, anterior aspect; c, left lateral aspect. 



ternally. The vertebrae are numerous and deeply biconcave (see 

 Fig. 40, A). They are primarily divisible into a precaudal 



