52 



MEMORANDUM. 



The following species, all contained in my original synoptical list, have also 

 since occurred in beds represented in its columns beyond what is there shown. 



In the Eed Ckag of Sutton and Butlet. — Nassa conglobata. A solitary specimen 

 found at Walton thirty-five years ago by Mr. Oharlesworth, and in my collection in 

 the British Museum, was the only instance of this shell known to me until lately. 

 In Mr. Canham's collection, however, I observed a specimen from the Red Crag of 

 Sutton ; and it seems to me, therefore, that although it has not yet occurred in the 

 Coralline Crag, this shell is properly a species of that Crag, and not of the Bed, 

 and is only present in the latter (albeit that it has occurred at Walton) by 

 derivation from the Coralline. 



In the Chillesfobd beds. — Cardita corbis and Abra prismatica. Mr. Dowson 

 informs me that he has found several specimens of these shells at Aldeby. 



In the Lower Glacial. — From a fossiliferous seam in the pebbly sands near 

 Southwold Mr. Crowfoot has obtained several of the species given in my original 

 list from these sands in Norfolk, and in addition Gerithium tricinctum, Mdampus 

 (Conovulus) pyramidalis, and Donax vittatus. Perfect specimens also of the latter 

 from Belaugh and Weybourn are in my cabinet. An imperfect specimen of 

 Gardium in my cabinet from Belaugh seems referable to Cardium Islandicum, 

 but no reliance can be placed upon such fragments, either in this or other beds, for 

 specific determination. Similarly, the fragments upon which the name of C. Groen- 

 landicwm is inserted in the list of shells given by Mr. C. Beid from these sands 

 where they underlie the Till along the Cromer coast (in the ' Geological Magazine ' 

 for July, 1877), are equally unreliable, and might be referred to more than one 

 large species of Gardium. Whether Islandicum or Grcenlandicum, the Belaugh 

 and Cromer fragments are probably those of the same species only, and would 

 answer as well for the one as for the other of these shells. Mr. Crowfoot also 



