12 THIRD SUPPLEMENT TO THE CRAG MOLLUSCA. 



justify a generic distinction. The hinge more resembles that of the latter shell, but that 

 species {Sphenia) has an internal connector. The name of Siliquaria (of Schumacher), as 

 given to the Oligocene shell by Dr. Speyer, is, I think, sufficient to guide us in our 

 future determination, for although I have many hundreds of specimens of Saxicava of 

 small size from the Coralline Crag, I have nothing that will fairly correspond with the 

 present shell. 



[The specimens have probably got into the Fluvio-marine Crag of Norfolk from the 

 same formation there which supplied those of Cerithium derivatum, Odostomia derivata, 

 and Odostomia Beevii. — Ed.] 



Cardium echinatum, Linn. Crag Moll., vol. ii, p. 152. 



As stated at p. 152 of my second volume this species has very rarely occurred in the 

 Crag, but a specimen has lately been found at Eelixstowe by Mr. W. E. Hardy, of Park 

 Crescent, Stockwell, which was sent to me for verification, and it is similar to the one 

 (now in the British Museum) figured in the ' Crag Moll.,' vol. ii, p. 152, Tab. XIV, 

 fig. 3. It belongs probably to the variety called ovafa by Dr. Jeffreys in ' Brit. Conch.,' 

 vol. ii, p. 271, and described by him as having the " ribs sharp." The Crag shell has 

 triangular ribs (unlike the common recent species, on which the ribs are quadrate), with 

 spines in a slight depression down the centre of these. The species is very rare in my 

 collection, I having found no other specimen than the one I gave to the British Museum. 

 This specimen is in good preservation with the exception of having lost all its spines. I 

 have a shell from the Sicilian beds which it more resembles, with sharp angular ribs 

 covered with broad spatulate imbricated spines, but Mr. Hardy's specimen, though well 

 preserved otherwise, has lost all. I do not know whether this Sicilian fossil has ever 

 been figured. 



Pecten disparatus, 8. Wood. 3rd Suppt., Tab. I, fig. 17. 



Locality. Red Crag, Waldringfield. 



The shell as above represented has been sent to me by Mr. R. Bell, but without a 

 name, and I know not to what published species it can be justly referred. I thought at 

 first that it might be one of tiie many varieties of that variable shell P. Danicus {septem 

 radiatus), but I have not been able to find one precisely similar in character ; and 

 although there is much resemblance to two or three other species, I have not been able 

 to assign it satisfactorily to any one. I have therefore given to it provisionally the above 



