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SUPPLEMENT TO THE CRAG MOLLUSCA. 



added more to our knowledge of living European and Atlantic Mollusca) sent me for 

 examination two specimens from the Mediterranean of a shell considered to be identical 

 with this species. These scarcely exceed half an inch in diameter, and if full grown would 

 be much more tumid than my Crag specimens. They were also more coarsely striated or 

 radiated. Under these circumstances I am not satisfied that Lajonkairii is a living species. 



Chama gryphoides, Linne. Crag Moll., vol. ii, p. 162, Tab. XV, fig. 8. 



Localities. As in ' Crag Moll.' 



When describing this shell in the ' Crag Moll.' I stated it to be very rare in the 

 Cor. Crag, and it has ever since continued so to my researches. The specimens found 

 by me in the Cor. Crag have always been very small or young individuals, while those 

 from the Red Crag appear all to be full-grown specimens or nearly so. The solidity of the 

 specimens would well protect them in a removal from one formation into another, and I 

 believe, notwithstanding its present scarcity in the Cor. Crag, that the specimens which have 

 been found in the Red Crag of Sutton are extraneous. 



In Mr. Jeffrey's List of Red Crag Shells appended to Mr. Prestwich's paper, ' Geol. 

 Journ.,' vol. xxvii, p. 482, this species is given as from Walton, but upon whose authority 

 is not stated. I have never seen it from that locality, but if it be so I should then be more 

 disposed to regard it as a denizen of the Red Crag Sea, and as additional evidence of the 

 greater antiquity of the Walton bed over the rest of the Red Crag. 



Verticordia cardiiformis, S. Wood. Crag Moll., vol. ii, p. 150, Tab. XII, fig. 18 (as 



Hippagus verticordius) . 



Locality. Cor. Crag, Sutton. 



Mr. Jeffreys in his list appended to Mr. Prestwich's paper (' Geol. Journ.,' vol. 27, 

 p. 139) has referred this Crag species to what he has called Pecc/iiolia acuticostata, and 

 he has obligingly sent me a single valve for examination. I find this recent shell to 

 differ from the Crag species in being much more tumid and in having the ribs more 

 elevated. In the recent shell these ribs are ornamented with a double row of very fine 

 spinulce, not a trace of which can I discover upon any of my Crag specimens. These may 

 possibly have been rubbed off, but the probabilities are that had they ever existed some 

 trace would remain on one or other of the ribs of the numerous well-preserved Crag- 

 specimens that I have examined ; but I can detect none. The number of ribs is probably 

 not a reliable character, but while this recent specimen had only fourteen ribs my Crag 

 specimens vary from that number to seventeen. I do not feel justified under these 

 circumstances in adopting the identification of the Crag shell with acuticostata. In my 

 'Eocene Bivalves' (page 138) I have given reasons for recurring to my original generic 

 name of Verticordia for the group of Mollusca to which the present shell belongs ; and in 

 consequence I have reverted to the specific name of Cardiiformis, under which I originally 

 sent it to the c Min. Con.' in 1844 (Tab. 039). 



