168 EOCENE MOLLUSCA. 
No. 107. VoxtuTa SeusErensis. JF. £. Edwards. Tab. XXII, figs. 3 a—/ 
VoLuTA LABRELLA. Sow. 1840. Min. Con., vol. vii, p. 8; t. 614, fig. 2. 
— — Morris. 1843. Cat. Brit. Foss., p. 167. 
— — Sow. 1850. Dixon’s Geol., &c., of Suss., p. 187; t. 5, figs. 12—14. 
BULBULA. — — — — — p. 186; t. 7, fig. 35. 
nec. — LABRELLA. Lamk. 1802. Ann. du Mus., vol. i, p.479, No. 10, vol, xvii, p. 74, 
No. 14. 
nec. — BULBULA. Lamk. 1802. Ann. du Mus., vol. i, p. 479, No. 11. 
V. testé ovato-turbinatd, ventricosdé, antice transversim sulcatd, ceterum levi ; spird 
brevi, conicd, apice acuto: anfractibus prioribus costas et sulcos tranversos, sese decussantes, 
gerentibus ; anfractibus ceteris unico sulco transverso prope margines suturales exaratis, 
marginibus ad spiram adpressis ; peripherid anfractuum primo convexd, deinde gradatim 
plus plusque rotundatd: apertura elongato-rhomboidal, antice profunde emarginatd, postice 
sub-canaliculatd ; labro postice incrassato, antice acuto, levi ; labio parum effuso, incrassato, 
postice magnum callum oblongum, anfractum a spird separantem, formanti ; columella 
leviter arcuatd, compressa, biplicatd. 
Shell ovately turbinate, ventricose ; spire short, conical, with a small, pointed apex ; 
the first two or three whorls ornamented with numerous slender longitudinal ribs 
decussated by transverse furrows, which disappear rather suddenly at the third whorl ; 
the whorls then become perfectly smooth, except towards the base, where they are 
traversed by broad more or less conspicuous furrows. The aperture is of an elongated 
rhomboidal form, deeply notched in front, and terminating posteriorly in an obscure 
channel; the outer lip smooth within, thickened behind, and stretching outwards 
into a wing-like projection; the middle and front parts thin and sharp-edged; the 
columellar lip but little spread out, and very much thickened, forming at the posterior 
extremity a large callus, which gradually separates the margins of the whorls more and 
more widely from the spire ; the columella is curved, flattened, and furnished with two 
oblique, nearly equal folds, and sometimes with a third feeble and indistinct one behind. 
The middle whorls are convex at the shoulders, but as they become more and more 
detached from the spire by the increasing callus, the shoulders become more and more 
bluntly round. 
The shells referred by Mr. Sowerby to /. dudbula are without doubt the young of 
the present species ; but even in this state (figs. 2 a, 6), although they much resemble the 
French shells, they present dissimilarities which sufficiently indicate a distinct species. In 
V. bulbula, the shell is more fusiform, with a longer spire; the margins of the whorls 
are without the transverse furrow ; the outer lip, even in the adult shell, is not thickened ; 
the inner lip is very thin, more widely spread over the body-whorl, and without the 
thickening or callus which distinguishes the present species; the columella is nearly 
straight and round; the folds are more slender, and placed nearer the middle of the 
