﻿330 



EOCENE MOLLUSCA. 



much arched, and is smooth within ; and that the columellar folds are more oblique, 

 more unequal, and not so prominent. 



Size. — Axis, 4-12ths of an inch ; diameter, rather less than 2-12ths of an inch. 



Locality. — Barton, where, apparently, it is rare. 



No. 252. Borsonia lineata. F. JE. Edwards. Tab. XXXIII, fig. 14, a, b. 



B. testa parvd, ovato-fusiformi, sub-turritd, lineis spiralibus costellisquelongitudinalibus 

 sese decussantibus, omnino clathraid: anfractibus convexis, postice sulco concentrico pro- 

 funde exaratis, ad sufuram lineato-marginatis ; lineis spiralibus elevatis, irregularibus ; cos- 

 tellis numerosis, angustis, pliciformibus, arcuatis : aperturd oblong o-ovali, antice in canali 

 brevi, latiusculo, exeunte ; labro sub-recto, postice profunde sinuato, intus plicifero ; colu- 

 mella parum tortuosd, biplicatd. 



Shell small, ovately fusiform, sub-turreted, and ornamented with concentric lines 

 and longitudinal ribs, imparting to the surface, by their decussation, the appearance 

 of a fine lattice-work ; the spire is of equal length with the aperture, and is rather 

 thick and pointed. The whorls, five or six without the pullus, are convex ; the 

 posterior margins slope very gently backwards, and are traversed by a deep, but not 

 very wide, furrow, feebly crenulated; the sutural edge is bordered either by a single, 

 rather thick, elevated line, sometimes granulated, or by a narrow band, formed of two 

 elevated lines, separated by a shallow, but perspicuous furrow ; the longitudinal ribs, 

 which are subordinate in character to the concentric lines, are not very prominent, 

 but numerous, narrow, fold-like, oblique, slightly arched, and sharply defined at their 

 posterior extremities by a concentric line, which borders the marginal furrow and 

 gives an angulated appearance to the shoulders ; in front of this are two equal, closely 

 set, not very prominent lines, and to these succeed other sharp, equal, transverse 

 lines, which become gradually more distant until they reach the anterior canal, over 

 which the transverse lines again approach more closely. The aperture is of a rather 

 narrow, oblong-oval form, and is produced in front into a short, moderately wide, canal ; 

 the outer lip is nearly straight, and presents, at the posterior margin, a deep, semi- 

 elliptical sinus ; the columella is slightly twisted, and bears at the middle two oblique 

 and nearly equal folds. 



This well-marked species is found at HighclifF ; it is somewhat rare. 



Size. — Axis, 7-24ths of an inch ; diameter, 2-12ths of an inch. 



