172 EOCENE MOLLUSCA. 
swelling into large, rounded tubercles. Aperture ovately rhomboidal, terminating 
behind in a narrow, but conspicuous, channel; outer lip smooth within, thickened 
towards the suture, otherwise thin and sharp-edged; inner lip narrow, thick, particu- 
larly at the posterior extremity, where it forms almost a callus ; columella curved, and 
furnished with two prominent folds in front, and sometimes a third faint one behind. 
The Volutes which I propose to separate under the present specific name, have been 
confounded hitherto with the preceding species (V. costata, Sol.) ; they appear, how- 
ever, to be specifically distinct. The shells are broad, obtusely angulated at the 
shoulders, with flattened sides; the ribs are more distant, thicker, and rounder, and on 
the last two whorls rise at the shoulder into large tubercles; the transverse lineation 
is more regular, and the aperture wider, and not contracted behind; the inner lip is 
much thicker, the columella more curved, and furnished with two folds, or, occasion- 
ally only, with a third faint one behind; and the base is much more bent backwards, 
owing to the deeper anterior notch. Specimens occasionally occur in which, owing to 
the tubercles being less prominent than usual, the spire is more regular in form, and 
the shells present a general resemblance to V. costafa ; but the whorls still preserve the 
flatness of the sides, and the ribs their characteristic roundness; and the condition of 
the columella and the inner lip show, in fact, that the individuals in question are merely 
a variety of the present species. 
Stze.—Axis, 2 inches and 2-10ths; diameter, 1 inch and 1-10th nearly. 
Localities— Barton, and Bracklesham Bay. 
Section A. (Pullus small, conical. 
b. Shell fusiform ; costated, transversely > continued. 
striated ; inner lip narrow) 
B. Columellar plaits numerous. 
No. 111. Votuta Maca. F. &. Edwards. Tab. XXII, figs. 2 a—/. 
VoLuTta MAGORUM. Sow. 1821. Min. Con., vol. iii, p. 164; t. 290, fig. 3. 
— — Morris. 1843. Cat. Brit. Foss., p. 168. 
— HARPULA. Sow. 1840. Min. Con., vol. vii, p. 7; t. 614, fig. 1. 
a — Morris. 1843. Cat. Brit. Foss., p. 167. 
— costaTA. Sow. 1850. Dixon’s Geol., &c., of Suss., p. 107, t. 5, fig. 24. 
i MAGNORUM (ex errore). D’Orb. 1850. Prod. de Paléont., vol. ii, p. 353, No. 281. 
—  opecora? Beyr. 1853. Die conchyl. des Norddeut. tertiarg. vol. 1, p. 73; t. 4, 
figs. 5 a—b. 
Nec. — MAGORUM. Broce. 1814. Conchol. foss., Subapen., vol. ii, p. 307; t. 4, fig. 2. 
nec. — HARPULA. Lamk. 1802. Ann. du Mus., vol. i, p. 478, No. 9, and vol. xvii, p. 78, 
No. 13. 
V. testé ovato-fusiformi, unduloso-costatd, inermi, transversim tenuissime striata, ad 
basin profunde emarginatd ; spird obtusa ; apice sub-acuto; anfractibus sex vel septem, 
