318 EOCENE MOLLUSCA. 
denticulatd, cinctis, ceterum laevibus; ultimo anfractu conico, antice in canali patulo 
indistincto, terminato, ad basin emarginato : aperturd angustd, sub-quadrata ; labro arcuato, 
acuto, intis plicato ; sinu latiusculo, sub-semicirculart, in margine collocato. 
Shell fusiform, somewhat turreted, longitudinally plicated, and transversely lined ; 
the spire conical, pointed, elevated, forming rather more than half of the shell. The 
whorls are sharply angulated at the shoulders ; the posterior margins slope gently back- 
wards ; they are deeply channelled, and are bordered round the suture by an elevated 
line, which, in some specimens, is sharp and ridge-like, in others denticulated ; the 
hollow space between this line and the shoulders is smooth; the last whorl is nearly 
conical, and terminates in front in a wide, indistinct canal, slightly emarginate at 
the extremity ; this form of the body whorl, with the conical spire, imparts to the 
shell the appearance of two cones placed base to base. The longitudinal plications, 
which extend to the very base of the shell, are numerous, narrow, oblique, curved, 
and thickened at the points, where they are crossed by the transverse lines, imto 
small, tooth-like tubercles ; the transverse lines are moderately distant and sharp. 
The aperture is very narrow and subquadrate, resembling that of the cones; the 
outer lip is moderately arched, sharp-edged, and strongly plicated within; the 
sinus, which is placed in the margin, is rather wide and nearly semicircular. 
Some shells from Lethen and Vliermael have been referred by Nyst to this species, 
although with doubt ; judging from the figure given by that author, the margins of the 
whorls in those shells appear to be narrower, and the longitudinal plications thicker and 
less numerous, than in this species, and the body whorl is convex, contracted in front, 
and terminates in a perspicuous canal ; the shells in question are, in fact, quite distinct 
from the “ festa ecaudata, utrinque sub-conica,”’ described by Solander, and D’Orbigny 
has distinguished them as P. sub-conoides. 
Size.—Axis, 9-12ths of an inclr; diameter, nearly 4-12ths of an inch. 
Localities. —Barton, Highcliff, Alum Bay (No. 29, Prestwich). 
No. 243. Pxievroroma Biconus. F. F. Rdwards. Tab. XXXIII, fig. 7, a, 6. 
P. testa biconicd, concentrice lineata: spird sub-turritd, acuminata: anfractibus ad 
humeros angulatis, granoso-tuberculatis ; postice cavatis, ad suturam lined fastigiiformi 
cinctis, ceterum levibus ; antice sub-rectis: lineis concentricis elevatis, acutis, sub-dis- 
tantibus, interstitiis concavis: aperturd angusto-ovali, in canali patulo indistincto exeunte ; 
labro leviter arcuato, acuto, intis plicato; sinu lato, breviusculo, sub-trigono, in margine 
collocato. 
Shell doubly cone-shaped and concentrically lined; the spire, which is a little 
shorter than the aperture, is somewhat turreted and pointed. The whorls, five or six 
without the pullus, are rather sharply angulated at the shoulders, which present 
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