26 



ICHTHYOPTERYGIA . 



Pig. 13. 



Ichthyosaurus trigonus. — Left lateral and anterior aspects of the centrum of 

 an early posterior dorsal vertebra ; from the Kirueridge Clay of Stanton. 

 §. a, upper, b, lower costal tubercle. 



of /. platyodon. The variations in the relations of the 

 costal tubercles are noticed in the above-mentioned 

 vertebral column of the latter species. Purchased, 1880. 



24684 d. The centrum of a large late posterior dorsal vertebra ; 



(Fig.) from the Kimeridge Clay of Wootton-Bassett. This 



specimen (fig. 14) agrees with Phillips's description (op. cit. 



Pig. 14. 



Ichthyosaurus trigonus. — Left lateral and anterior aspects of the centrum of 

 a late posterior dorsal vertebra ; from the Kimeridge Clay of Wootton- 



Bassett. 



a, upper, b, lower costal tubercle. 



p. 336) of the 40th vertebra; the outline of the face 

 narrowing upwards, and the height being nearly equal to 

 the width. The length of Phillips's specimen is, however, 

 said to be greater. Cunnington Collection, 



