GASTEROPODA. 151 



1. Marsenia tentaculata. 3Iont. Tab. XV, fig. 10. 



Lamellaria tentaculata. Montague. In Linn. Trans, vol. ii, p. 186, t. 12, fig. 5-6, 1815. 



— LovcH. Ind. Moll. Scand. p. 15, 1846. 



Marsenia depressa. S. Wood. Catal. in An. and Mag. Nat. Hist. 1842, p. 528, t. 5, fig. 8-9. 

 SiGARETus tentaculatus. Thorpe. Brit. Marine Conchology, p. 155, t. 1, fig. 3, 1844. 



N. Testa minutd, ovatd, auriformi, tenui, frat/ili, peUuciddQ), lavigatd, politd ; spird 

 depressd; anf radii convexiusculo ; aperturd patente ; labro acuto arcuato ; labia tenui 

 reflexo. 



Shell small, ovate, or ear-shaped, thin, fragile, and pellucid (?), smooth and glossy, 

 with one depressed or slightly convex volution ; spire rather acute, with a large 

 expanded aperture, and curved outer lip ; columella, sharp and truncate ; inner hp 

 thin and extended, covering the umbilicus. 



Greatest diameter, \ of an inch. 



LocaUty. Cor. Crag, Sutton. Recent, British Seas. 



Two small specimens of this elegant and fragile shell are all that my cabinet 

 contains. They are probably the young state of Lamellaria tentaculata, Mont., and 

 appear to resemble the figure of that species given by Mr. Thorpe, above referred to, 

 except that the outer part of the lip of our shell is not quite so much raised. There 

 is a slight depression behind the sharp edge of the columella, which is visible within 

 the shell up to the apex ; the inner lip is thin, folded over this sharpened edge, and 

 spread upon the body of the shell to some distance. The contour of our shell is a 

 trapezoidal form, with the angles rounded off. 



Velutina,* Fleming, 1820. 



Helix (spec.) Linn. 

 Bulla (spec.) MuUer. 

 Velutina. Gray, 1821. 



— Be Blainv. 1825. 



Galekiculum. Brown, 1827. 



Gen. Char. Shell thin, obliquely convolute, with very few volutions, rapidly 

 enlarging ; spire short, slightly elevated, externally smooth, or finely striated, covered, 

 in a recent state, with a thick epidermis ; aperture large, ovate, or suborbicular ; outer 

 lip sharp, with a continuous peritrcme. 



Shells of this character were erected by Dr. Fleming into a genus, the particulars 

 of which were given in the 'Edinburgh Encyclopoedia,' vol. xiv, p. 626, published, as 

 I am informed, by Dr. Fleming, in 1820. In the following year, 1821, Mr. Gray 

 employed this name generically, and in 1825 M. de Blainville (in his Malacologie, 



* Etym. From tlie specific name of Bulla velutina (Miiller), the type of the genus. 



