GASTEROPODA. 151 



1. Marsenia tentaculata. Mont. Tab. XV, fig. 10. 



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



— Loven. 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, fragili, pellucidd (?), laevigata, politd ; spird 

 depressa ; anfractu convexiusculo ; aperturd patente ; labro act/to arcuato ; labio 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 

 lip thin and extended, covering the umbilicus. 



Greatest diameter, \ of an inch. 



Locality. 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.) Mutter. 

 Velutina. Gray, 1821. 



— Be Blainv. 1825. 



Galericulum. 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 subor- 

 bicular ; outer lip sharp, with a continuous peritreme. 



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

 of which were given in the ' Edinburgh Encyclopedia,' 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, 



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



