304 EOCENE MOLLUSCA. 
wider apart, being separated by spaces as wide as themselves ; they are flattened on 
the upper surface and roughened by the lines of growth. The whorls present a series 
of faint, almost obsolete, longitudinal, curved plications, representing the successive 
edges of the outer lip, and which on the last whorl extend almost to the base. The 
aperture is nearly oval, and terminates in front in a wide, short, and oblique canal ; 
the outer lip is much arched, thin, and sharp-edged ; and the sinus, which is placed 
on the shoulder, is very wide, deep, and almost semicircular in shape. 
Size.—Axis, nearly 6-12ths of an inch; diameter, not quite 2-12ths of an inch. 
Locality.—Clarendon, where it apparently is very rare. 
No. 229. Pievurotoma Woop. F. #. Edwards. Tab. XXXII, fig. 10, a, 6. 
P. testa turriculatd, omnino concentrice lineata : spird elevatd, acuminata : anfractibus — 
planulatis, ad humeros obtuse angulatis, et carind latissimd, rotundatd, in medio spiraliter | 
suleatd, instructis ; marginibus posticis angustissimis, depressis: lineis concentricis supra 
partes medias et anticas anfractium sub-distantibus, latis, depressis ; supra carinam et 
margines posticas fere obsoletis: aperturd sub-quadratd, in canali brevi exeunte : labro 
parum arcuato ; sinu semicirculari, ad carinam collocato. 
Shell turreted and spirally lined, with a pointed, elevated spire, rather longer 
than the aperture ; whorls, eight, exclusive of the pullus, nearly straight at the sides, 
and obtusely angulated at the shoulders, where they present a very broad, prominent, 
rounded keel, traversed along the middle by a narrow and shallow furrow, repre- 
senting the progress of the extremity of the sinus; the posterior margins are exceed- 
ingly narrow, depressed, and concave, and are simple on the sutural edge. The concentric 
lines over the middle and front parts of the whorls are rather numerous, regular, 
band-like, depressedly convex on the upper surface, and separated by deep concave 
furrows, equalling the bands in width; over the keel and posterior margins the con- 
centric lines are nearly obsolete. On the early whorls the lines of growth are very 
perspicuous, resembling small, oblique coste ; these are lost on the last two whorls. 
The aperture, owing to the somewhat flat sides and the depressed posterior margin of 
the whorls, is subquadrate in form, and terminates in front in a short, moderately wide 
canal, rendered slightly oblique by the curve of the columella; the outer lip is very 
little arched, almost straight, and is smooth within; and the sinus, which is on the 
keel, is moderately wide and semicircular. 
This well-marked Pleurotoma is extremely rare ; I have dedicated it to Mr. Searles 
Wood, by whom it was discovered, and to whose liberality I am indebted for the 
specimen figured. 
Size.—Axis, 5-12ths of an inch, nearly; diameter, 2-12ths of an inch. 
Locality —Headon Hill. 
