222 EOCENE MOLLUSCA. 
Acy-en-Mulcien, Fosse-Martin, Ermenonville, Ver (fide Graves), Laon (fide 
Mellev.), Bos dArros (fide Rouault). North American— Claiborne, Alabama (fide 
d Orb.) ? 
No. 147, PLEUROTOMA TEXTILIOSA, Deshayes. Tab. XXVI, fig. 7. 
PLEvRotoMA TEXTILIOSA, Desh. 1824-37. Desc. des coq. foss., &c., vol. ii, p. 454, t. 62, 
figs. 5, 6. 
— —_ D’ Orb. 1850. Prod. de Paléont., vol. ii, p. 417, No. 1480. 
P. testé elongato-fusiformi, angustd, sub-turritd, longitudinaliter costatd, spiraliter 
subtilissime lineatd ; spird elevatd, acuminata : anfractibus sub-convenis, angulatis ; margi- 
nibus posticis angustis, concavis, ad suturam inerassatis ; costis distantibus, obtusis ; lineis 
spiralibus confertis, inequalibus, lineis incrementi sub-decussatis: apertura ovato-angusta, 
mm canali mediocrs exeunti ; labro acuto ; sinu lato, trigono, in margine collocato. 
Shell elongate, fusiform, narrow, longitudinally ribbed and ornamented with 
numerous, very fine, concentric, raised lines; the spire, which is formed of eight or 
nine volutions exclusive of the pullus, is poimted and much produced, fully equalling 
the last whorl in length : the whorls are slightly convex, and angulated at the shoulders ; 
the posterior margins narrow, hollowed out, and thickened at the edges so as to form 
an elevated border round the suture; the whole of the margin is covered with very fine, 
regular, closely set, concentric lines, of which those on the border are more conspicuous 
than the rest. The longitudinal ribs are rather distant, round, thick, and short, barely 
extending to the middle of the whorls, and terminating abruptly at the shoulders, 
where they present a sharp keel-like edge, which gives somewhat of a turreted aspect 
to the spire. The concentric lines over the front and middle parts of the whorls are 
very numerous, unequal, and irregular; some of them, slender and thread-like, are 
prominent and more or less distant, and the intermediate spaces are covered with 
exceedingly fine lines, scarcely perceptible by the naked eye; the whole are roughened 
by the lines of growth. The aperture is of a narrow, ovate form, and terminates in 
front in a moderately long canal, slightly notched at the anterior extremity ; the outer 
lip is thin, sharp-edged, and expanded behind; the sinus which is wide, deep, and 
somewhat trigonal in form, is placed a little in front of the middle part of the 
posterior margin of the whorl; the columella is slightly twisted and presents a con- 
spicuous but not very prominent crest. M. Deshayes states that the columella is 
“sub-perforated at the base,” presenting there a narrow, shallow “ umbilical opening, 
partly covered by the inner lip;” this opening, however, is not truly umbilical, but a 
shght hollow caused by the ridge or crest being imperfectly overlapped by the inner 
lip, and is a character very variable, and sometimes wanting. 
