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. PLEurRoroma GraNutata. Lamk. Tab. XXVIII, fig. 4, a—e. 
PLEUROTOMA GRANULATA. Lamk, 1804. Ann. du Mus., vol. iii, p. 266, No. 21; vol. vii, 
t. 13, fig. 4, a, 6. 
— — Lamk. 1822. Hist. nat., &c., vol. vii, p. 101, No. 26. 
_ — Desh. 1824-37. Descr. des Coq. foss., &c., vol. ii, p. 476; t. 67, 
figs. 1—3. 
Non PLEUROTOMA GRANULATUM. PAil. 1851. Tert. foss. Magdeb. (Paleeontograph., vol. 1, 
p- 67, No. 127; t. 9, fig. 13). 
Var. rormosa (Charlesw.). P. testa clongato-fusiformi, sub-turritd, longitudinaliter 
granulato-costellatd, concentrice lineata: spird productd, dimidium totius teste in longitudine 
paullulo superanti: anfractibus convexiusculis, sub-angulatis, postice sub-canaliculatis, ad 
suturam granulatis ; costellis numerosis, undosis, fere ad basin tendentibus ; lineis concen- 
fricis crebris, duabus vel tribus lineis posticis proeminentioribus : apertura oblongo-ovali, 
in canal 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 
