﻿264 



EOCENE MOLLUSCA. 



backwards, slightly channelled, a little thickened on the sutural edge, and bordered by 

 a thickish raised line, the space between which and the shoulder is ornamented with a 

 series of rather closely set, curved plications, formed by the successive margins of the 

 sinus. The spiral lines are very faint, scarcely visible to the naked eye, over the 

 margins of the whorls, but elevated, thread-like, and irregular over the middle and 

 front parts, where they are strongly decussated by the lines of growth, which are 

 prominent and regular ; the surface of the whorls is finely cancellated by these 

 decussating lines, suggesting the idea of the shell being covered with very 

 fine linen ; whence the name. The posterior line, girding the shoulders, is more 

 elevated than the rest, giving the whorls the appearance of being sharply carinated ; 

 on the early whorls this posterior line is broken into oblong denticulations, which 

 disappear as the shell approaches maturity. The aperture is of an oval form, and 

 terminates in front in a short, wide canal ; the outer lip is slightly arched, and 

 presents a moderately deep sinus, extending across the margin, and somewhat 

 triangular in form. 



This very pretty shell appears to be quite distinct ; it is rare. 



Size. — Axis, 5-12ths of an inch nearly ; diameter, not quite 2-12ths of an inch. 



Locality. — Stubbington. 



No. 186. Pleurotoma granulata. Lamh. Tab. XXVIII, fig. 4, a — c. 



Pleurotoma granulata. Lamk. 1804. Ann. du Mus., vol. iii, p. 266, No. 21 ; vol. vii, 



t. 13, fig. 4, a, b. 



— — Lamk. 1822. Hist, nat., &c, vol. vii, p. 101, No. 26. 



— — Desk. 1824-37. Descr. des Coq. foss., &c, vol. ii, p. 476; t. 67, 



figs. 1—3. 



Non Pleurotoma granulatum. Phil. 1851. Tert. foss. Magdeb. (Palseontograpb ., vol. i, 



p. 67, No. 127; t. 9, fig. 13). 



Far. Formosa (Ckarlesw.). P. testa elongato-fusiformi, sub-turritd, longitudinaliter 

 granulato-cosiellatd, concentrice lineatd: spird productd, dimidium totius testa in longitudine 

 paullulo super anti : anfractibus convexiusculis, sub-angidatis, postice sub-canaliculatis, ad 

 suturam granulatis ; costellis numerosis, undosis, fere ad basin tendentibus; lineis concen- 

 tricis crebris, duabus vel tribus lineis posticis proeminentioribus : aperturd oblongo-ovali, 

 in canali brevi, latiusculo exeunti ; labro aliforme; sinu lato, sub-semicirculari, in margine 

 collocato. 



Shell elongated, fusiform, ornamented with numerous longitudinal, narrow ribs, 

 which are crossed by concentric, raised lines, and thickened into small, round knobs at 

 the points of intersection, imparting a granulated character to the surface : the spire, 

 formed of seven or eight volutions, is rather obtuse, and moderately elevated, somewhat 



