226 CRETACEOUS LAMELLIBRANCHIA. 



Ostrea Nilssoni has been referred by Bohm, Stolley, Grronwall, and Ravn to the 

 genus Dimyodon, Munier-Chalmas. 1 When describing Plicatula sigillina I remarked 

 that although it belonged to a type distinct from the other Cretaceous species, yet 

 it resembled the recent form Plicatula phillvpinarum, Hantz. I have not seen 

 the adductor impressions in any specimens of Plicatula sigillina, but nevertheless 

 I think that it is quite possible that the authors mentioned may be correct in 

 referring this species to the genus Dimyodon, Munier-Chalmas. 



Dimyodon costatus, Grronwall, seems to be very closely related to D. Nilssoni. 



Page 152. Pecten Nilssoni, Goldf., Plate XLII, figs. 9, 10. Through the 

 kindness of Mr. J. P. J. Ravn I have received specimens of P. Nilssoni from the 

 Chalk of Faxe, and I am now able to state that I consider that the specimens 

 from Trimingham, mentioned on page 152, and also another from the Act. quad- 

 ratics zone of Hampshire (coll. R. M. Brydone), are referable to that species. 



1 In Fischer's 'Manuel de Conchyliol.' (1886), p. 957. 



