258 



>/ the Asiatic Society of 



[May, 1910.] 



related to the Pinnidae, and Futterer has described the Alpine 



specimens under the 



generic 



name of Pinna. Douville has 



wi 



(J^mptes-rendus des seances de la Societe geologique de France 

 e " irv ^^ """ Stanton has suggested a relation to the 



m 190 

 group of the Fectinida?. perhaps to Hinnites 



Hoernes 



1902, pp. 667-684), from his own 



lm, has shown that the structure 



of the shell in which the ribs affect only the external layers, 



inner 



from the 



tinct prismatic layer, clearly separate, this genus 

 Pinnidae, while bringing into close connection with the Ostreidse. 



In all instances the shells of Chondrodonta whether from 

 Europe, Asia, or America appear to accompany deposits con- 

 taining shells of the Rudistae. It may be noticed that the closely 

 related form from the Venetian Alps occurs with an association 

 of fossils closely similar to the Seistan species, and that the 

 Alpine beds have been referred by several authors to the Turo- 

 nian, which is also approximately the age which I suggested for 

 the Seistan fossils, that is upper Turonian or at the limit of 

 Turonian and Senonian. 



