PLATE 20 

 Peridinium oceanicum Vau H. 

 From Sausalito, California, February 13, 1912 

 Fig. 7. A'entro-apical view. X 1500. 

 Fig. 8. Lateral view. X 1500. 



Note that the ventral epitheeal plate pattern is that of the subgenus, Para- 

 peridinium, rather than that of the subgenus, Ortlio peridinium, usually found in 

 P. oceanicum. It is possible that this particular specimen may be more closely 

 related to a race of P. depressum Bail, than to a race of P. oceanicum Vanh. 



[478] 



