152 EOCENE MOLLUSCA. 
V. testd ovato-oblongd, costatd, transversim sulcatd, antice sub-profunde emarginatéa ; 
spird brevi, acuminata : anfractibus convexiusculis, und serie spinarum dentiformium 
coronatis, ad margines suturales planatis ; costis numerosis, angustis, acuti-nodosis, ad 
basin tendentibus: apertura elongato-angusta ; labro intus incrassato, plicato, ad mar- 
ginem crenulato ; columella triplicata. 
Shell oblong-oval, ribbed, transversely sulcated, rather deeply notched at the base; 
spire short, pointed; the ribs narrow, rather numerous, extending to the very base of 
the whorl: whorls rather convex, crowned by a single row of short, erect, sharp tooth- 
like spines, between which and the suture the margin is flattened, forming a narrow 
channel or ledge, which runs round the spire and gives a turreted aspect to the shell. 
The furrows are separated by a narrow line, which rises into small pointed knobs, where 
it crosses the ribs, and are roughened by numerous sharp, perspicuous lines of growth ; 
the last furrow, immediately in front of the spines, is wider than the rest. The aperture 
is long and narrow; the outer lip thickened, plicated within, and crenulated on the 
margin; the inner lip is not much spread over the body whorl, and does not extend 
backwards beyond the suture. 
In the French shells the ribs are close and broader; the elevated parts, where 
they are crossed by the furrows, are consequently blunter and more nodiform than in the 
English shells; the ribs also, instead of bemg crowned with erect pointed spines, 
terminate in thick round knobs, which extend partly over the margin towards the 
suture, and the outer lip, although thickened, appears to be not plicated within. Dr. 
Beyrich considers /. dima to be a different species to /. digitalina ; but in all respects, 
except those pointed out, the two agree so well that, notwithstanding this high autho- 
rity to the contrary, Iregard the French shell as a local variety only of Brander’s Buce. 
scabriculum. 
The shell from Bracklesham Bay, figured in Mr. Dixon’s work (t. 5, fig. 22) as 
V. crenulata, belongs in fact to this species. Defrance, indeed, suggests that V. scabra- 
cula may probably be only a variety of V. crenulata, modified by local conditions. 
It is difficult to ascertain to what extent specific characters may be modified by 
external conditions; but the different sculpture, the narrower aperture, the deeper 
notch, the less effuse inner lip, and the thickened plicated outer lip of the shells under 
description, appear to me to justify their being retaimed as a distinct species. 
Size.—Axis, 1 inch and 4-10ths nearly ; diameter, 6-10ths of an inch nearly. 
Localities.—Barton, Alum Bay (Stratum No. 29, Prestwich), Highcliff, Bracklesham 
Bay. Srench: Valmondois, Betz, Monneville, Tancrou (fide Desh.). 
