TAB. XIX. 



Ichthyosaurus. 



Cranial and vertebral characters. 

 Fig. 



1. Skull, lacking end of snout, upper view {Ich. longifrons, Ow.). 



2. Centrum of atlas vertebra, front view (ib.). 



3 lb. upper view (ib.). 



4 lb. back view (ib.). 



5. Atlas and axis vertebrae, side view (ib.). 



6. Atlas, axis, and third vertebrae, side view {Ich latifrons). 



Mgs. 1 — 5 are from the Upper Lias. 

 Pig. 6 is from the Lower Lias. 



(All the figures are of the natural size.) 



