58 CHASTER : BRITISH MARINE MOLLUSCA. 



Lepton sykesii, Chaster. 

 Ann. and Mag. Nat. Hist., Mar., 1895, p. 248. 



Mr. Marshall is quite correct in his supposition that it is my 

 species that he described and figured in the " Journal of Mala- 

 cology" of June last. His figures represent the outline and 

 general appearance of the shell remarkably well, although the 

 sculpture is not shown, the concentric markings seen in the sketch 

 of the exterior not even suggesting the character of the sharply 

 defined and regularly placed lines seen on the shell. Respecting 

 the structure of this hinge I was able to satisfy myself as to its 

 true nature, only by examining it in a live specimen the valves of 

 which had been separated and deprived of the cartilage by careful 

 boiling in dilute caustic soda solution. It is true that the 

 minute cardinal I described is not very readily detected when the 

 valve is examined in the usual flat position. If, however, this be 

 placed almost \ertically with the dorsal area uppermost it is 

 quite apparent, and vah'es, even in the more or less worn state 

 usual with dead shells from Ouernsey dredgings, generally 

 exhibit some trace of it. 



The species is not, in my opinion, a member of the 

 " Neolepton " group as Mr. Marshall declares. Neolepton is 

 described by its founder Monterosato, in his " Nomenclatura," 

 as follows : — •' Genere proposto per le specie oblique che hanno 

 una scultura concentrica ed il cardine di altra struttura. ' Now 

 L. svkesii agrees with Lepton proper in its sub-rhomboidal outline 

 and in its hinge, the latter, it is almost needless to say, l)eing the 

 most important character for purposes of classification. The hinge 

 teeth are quite similar to those of L. nitidum, Turt., even in their 

 position, the cardinal in the right valve being placed midway 

 between the laterals, whilst that in the left valve is close to the 

 posterior lateral. 



This species is by no means restricted to the Channel 

 Islands for I have it from other localities, having met with it in 

 material from Mounts Bay, Cornwall, dredged by Mr. G. F. 

 Tregelles, as well as in my own recent dredgings there. I also 

 found a valve in shore-drift from Dogs' Bay, Connemara, 

 collected this summer by Mr. R. Standen. 



Crenella pellucida, Jeff., sp. 

 1S59, Lhuopsis pellucida, Jeff., Ann. and Mag. Nat. Hist., p. 12, pi. 11 , fig. 6. 

 Mr. Marshall's reference {loc. cit.) to this species seems 

 wholly irrelevant, and is, moreover, unfortunate in containing 



