456 



MESOZOIC TIME REPTILIAN AGE. 



murus commxinis; fig. 709, head of same; figs. 710 a, 710 b, view and sectior 

 of vertebra; fig. 711, tooth of same, natural size. Fig. 712, Plesiosaurus dolicho- 



Fis. 707. 



Ganoid.— JEchmodus (Tetragonolepis) (X }/&)', a, 



Figs. 708-714. 



of same. 





Reptiles.— Fig. 708, Ichthyosaurus communis (XiJo); 709, Head of same (X<&); 710 a, 

 710 b, view and section of vortehra of same (X V&)\ 711, Tootli of same, natural size; 712, 

 Plesiosaurus dolichodeirus (X jfo); 713 o, 713 b, view and section of vertebra of same; 714, 

 Mystriosaurns Tiedmanni. 



