PLATE LxX, 



described by authors, as the figures in the annexed plate will fully 

 express. 



Da Costa has not noticed this species, though it must have been 

 known to him from the figures and descriptions in Pennant's Zoology, 

 where it stands under the name of M. Curtus. sp. 76. A. Short. Pen* 

 nant's specimen scarcely exceeds the size of the second specimen 

 figured in our plate ; — it was described from a Shell in the Portland 

 Cabinet, that had been taken at Weymouth. 



Linnaeus mentions this species in the Fauna Suecica. Gmelin 

 quotes the Works of Chemnitz for its figure, where it appears some- 

 what smaller than in those of Pennant. It is certainly very scarce. 



