GASTEROPODA. 121 



1. FossARUS suLCATus. S. JFoocI. Tab. VIII, fig. 23, a — d. 



Phasianema sulcata. S. Wood. Catal. of Shells from the Crag, in An. and Mag. Nat. Hist. 



1842, vol. ix, p. 935, pi. 5, fig. 15. 

 — lineolata. S. Wood. Catalogue, var. /3. 



FossARCS CLATHRATCs. Phil. En. Moll. Sic. vol. ii, p. 148, t. 25, fig. 5, 1844. 



F/t. Testa ovafo-fusiformi ; apice obtuso; anfradibus tribus, comexis ; transversim 

 sulcatis ; interstitiis longitiidinaliter plicatis ; suturis depressis ; lahro acuto ; columella 

 paululum uniplicatd. 



Shell ovato-fusiform, with an obtuse apex ; volutions three, convex ; transversely 

 sulcated, or rather ridged; longitudinally and finely plicated between the ridges; 

 aperture large, ovate, acuminated at the upper part ; outer lip sharp ; inner one shghtly 

 replicate, with a small fold upon the columella. 



Axis, I of an inch. 



Locality. Cor. Crag, Sutton. Recent, Mediterranean. 



Var. /3, lineolata (fig. 23 c, d) was considered in my Catalogue as a distinct species, 

 the sulci or ridsces beings CTeater in number, with a more tumid form in the volutions. 

 The acquisition of more specimens has, however, removed some of these distinctions, 

 and I am compelled now to include it only as a variety. About eight or ten elevated 

 ridges cover the exterior of var. a, and these are sometimes at irregular distances, the 

 furrows or spaces between them being wider than the ridges, and crossed by imbri- 

 cated lines of growth; the shell is thin, and the ridges are visible from within. 



This species is in all probabihty the same as M. Phihppi has figured at the above 

 reference, though his shell appears to be larger, with fewer elevated ridges. I have 

 no specimen with less than eight, while some have as many as fifteen ridges, as in 

 var. /3. In my specimens there is a thickening, or an obsolete tooth, about the middle 

 of the columella, close to the umbilicus. 



Lacuna, Turton, 1827. 



Temana. Leach, MS. 1819. 

 Turbo (spec.) Mont. 

 Lute A. Breton, 1827. 

 Maceomphalus. iS. Wood, 1842. 



Gen. Char. " Shell thin, conoid, or somewhat globular, clothed with an epidermis ; 

 aperture entire, rounded or oval, with the hps* disunited at the top ; pillar flattened, 

 with a longitudinal groove, which terminates at the upper end in an umbihcus ; 

 operculum horny." 



The above characters are given by Dr. Turton for this genus in the third volume of 

 the 'Zoological Journal,' p. 190, where he also describes seven species, all of which 

 appear to have a smooth exterior. Its principal distinction appears to be the elongated 

 depression behind the edge of the inner margin of the aperture. 



16 



