﻿266 



EOCENE MOLLUSCA. 



Shell slender, fusiform, longitudinally ribbed, and concentrically furrowed ; spire 

 pointed, elevated, forming rather more than half of the whole shell ; whorls, six or 

 seven, flatly convex ; slightly thickened at the posterior edge, and bordered by a 

 spiral, sharp, elevated, ridge-like line, which runs round the sutural margin, the 

 space between which and the shoulder presents a deep, round furrow, obliquely 

 plicated by the successive margins of the sinus. The longitudinal ribs are numerous, 

 oblique, rounded, and very short, barely extending to the middle of the whorl, 

 and frequently altogether lost on the last w T horl; the spiral furrows are regular, 

 moderately distant, and rather deep. The aperture is of a lengthened, ovate form, 

 and terminates in front in a short, but distinct, and moderately wide, canal ; the sinus 

 is somewhat three-cornered in shape, wide, but not very deep, and placed in the 

 margin. 



Size. — Axis, 3-10ths of an inch ; diameter, 1 -8th of an inch. 

 Localities. — Headon Hill, Colwell Bay, Hordwell (Upper Marine formation), 

 Lyndhurst; and WhiteclifT" Bay (fide Forbes). 



No. 188. Pleurotoma vicina. F. E. Edwards. Tab. XXIX, fig. 10, a, b. 



P. testa parvd, politd, gracili, fusiformi, omnino concentrice crebri-sulcatd : spird 

 sub-conicd: anfractibus planulalo-convexis, in juventd costellatis et sub-angulatis ; mar- 

 minibus posticis declivis, vix cavatis, plicatis, unicd lined elevatd prope suturam cinctis ; 

 uperturd angustd, ovali, aniice in canali brevi, lato exeunti ; labro acufo. arcuato ; sinu 

 lato, sub-trigono, anticd hi margine collocato. 



Shell small, polished, slender, fusiform, ornamented with numerous, close-set, 

 shallow furrows : the spire elevated, forming rather more than half of the shell ; 

 the whorls, six or seven, very slightly convex ; the posterior margins, which slope 

 gently backwards, are nearly straight, giving a sub-conical shape to the spire, and are 

 girt round the suture by a single elevated, ridge-like line, in front of which appears a 

 series of numerous curved plications formed by the successive margins of the sinus. 

 The early whorls are obliquely ribbed and slightly angulated at the shoulders, but 

 both these characters disappear as the shell approaches maturity. The aperture 

 is of a narrow, oval shape, and terminates in front in a short, wide canal ; the outer 

 lip is sharp on the edge, arched, projecting most towards the anterior extremity ; and 

 the sinus, which is wide, moderately deep, and sub-trigonal in form, is placed in the 

 very front of the margin. 



This shell very closely resembles P. Ileadonensis, of which it may perhaps prove 

 to be merely a variety. It is distinguished by the more slender form, the shorter 

 spire, the more closely furrowed and less convex whorls, the absence of the costella', 



