18 



Annals of the South African Museum. 



V 



and also P. cereviciana, Petho, :;: from the Senonian of Cereviic 

 (Hungary). But more perfect specimens are needed before an 

 exact determination can be made. The ligament grooves are less 

 numerous and more widely separated than in P. cereviciana, but 



j? IG 6. Perna, sp. Internal cast. A considerable portion of the posterior part 

 of the shell appears to be missing, x . 



the flattened part of the shell extending ventrally from the umbo is 

 similar in both species. 



* Die Kreide- (Hypersenon-) Fauna d. Peterwardein. Gebirges (Palseonto- 

 ^raphica, lii., 1906), p. 234, pi. xvii. 



