328 EOCENE MOLLUSCA. 
the spire, one of the transverse lines near the middle is more elevated than the 
others, and the columella sometimes presents a third fold, much smaller than the 
other two. In all other respects the shells from the two localities agree perfectly, 
and the differences do not appear to me to be sufficient to justify their being considered 
as specifically distinct. 
The shells which Rouault, in the first instance, separated under the specific name 
Palensis were subsequently ascertained by that author to be the adult shells of B. 
Biaritzana, and were united by him to that species. 
Size.—Axis, ] inch and 5-12ths; diameter, 7-]2ths of an inch, nearly. 
Localities—Bracklesham Bay and Bramshaw, at both of which places it is not 
uncommon. french: Bos d’Arros. 
No. 250. Borsonia sutcata. F. #. Edwards. Tab. XXXIII, fig. 12, a, 6. 
Borsonta suteata. Morris, 1856. Forbes’s Tert. fluvio-mar. Form., &c., p. 154, t. 5, 
fig. 3, 3 a, 3 6. 
B. testa ovato-fusiformi, semi-costatd, transversim sulcatd ; spird sub-turritd, acuminata : 
anfractibus convextiusculis ; marginibus postices excavatis, ad suturam marginatis, ceterum 
levibus ; costis crassiusculis, rotundatis ; sulcis transversis sub-distantibus, irregularibus : 
apertura oblongo-ovatd, in canali perbrevi, latissimo, exeunte ; labro arcuato, postice sinuato, 
antis plicato; sinu lato, paululum profundo, rotundato: columella oblique biplicatd, plicis 
sub-equalibus. 
A small, ovately fusiform shell, longitudinally ribbed and spirally furrowed ; the 
spire, formed of from six to eight volutions, is moderately elevated, rather exceeding 
the last whorl in length, and is somewhat turreted. The whorls are slightly convex; a 
deep, smooth furrow runs round the posterior margins, which are bordered round the 
suture by an elevated, ridge-like line; the last whorl is nearly conical, and terminates 
in front in a short, but distinct, and very wide canal. The longitudinal ribs are rather 
broad, very short, not extending beyond the middle of the whorls, and are lost on the 
last whorl of the mature shell; the spiral furrows are wide, rather deep, concave, 
somewhat distant, and separated by spaces wider than themselves, and rounded on 
the upper surface. The aperture is of an oblong-ovate form; the outer lip is mode- 
rately arched, sharp on the edge, and plicated within ; and it presents, at the posterior 
extremity, in the marginal furrow, a wide, but not very deep, rounded sinus ; and the 
columella is slightly arched, and bears, about the middle, two nearly equal, moderately 
oblique folds. 
In general aspect this species presents a strong resemblance to Borsonia (Pleuro- 
toma) nodularis (Desh.) ; but in that species the shell is wider and shorter, and the 
surface is nearly smooth, except over the canal, which is traversed by a few concentric, 
