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EOCENE MOLLUSCA. 



postice sidco spirali, exilissime lineato, exaratis ; ad suturam duplici lined elevate!, undulatd 

 marginatis ; ultimo anfractu in cauali brevi, latiusculo, recurvo, desinente : lineis spirali- 

 bus alternatim crassis et tenuissimis ; lineis crassis per-elevatis et per lineis incrementi 

 granulatis : aperturd ovali ; labro leviter arcuato ; sinu lato, mediocriter pro/undo, sub- 

 trigono, ad humerum collocafo ; columella arcuatd, cristatd. 



Shell elongate, fusiform, and ornamented with concentric, granulated, raised lines ; 

 spire thick, nearly conical, and much produced, fully equalling three fifths of the entire 

 shell in length. The whorls, eight exclusive of the pullus, are slightly convex, and 

 girt round the shoulders by a single row of small, oblong, curved, comma-like tuber- 

 cles ; the posterior margins are nearly straight, and furrowed by a broad, deep sulcus, 

 which is traversed by a few concentric lines, so faint as scarcely to detract from the 

 smoothness of the surface ; the sutural edge is thickened, and bordered by two closely 

 set, undulating, sharp, raised lines ; the last whorl contracts somewhat suddenly in 

 front and terminates in a short, rather wide, and curved canal, slightly bent backwards 

 at the anterior extremity. The spiral lines are unequal, thick prominent lines alter- 

 nating with very slender, thread-like lines ; the larger lines are granulated with much 

 regularity by the successive margins of the outer lip ; the smaller lines are but faintly 

 decussated. The aperture is rather widely oval ; the outer lip slightly arched and 

 sinuated at the shoulder ; the sinus very wide, moderately deep, and triangular in 

 form ; and the columella, which is a little twisted, presents a small crest in front. 



This species presents an elegant ornamentation, quite distinct in character from 

 that of any other English Eocene Pleurotoma. It appears to be exceedingly rare. 



Size. — Axis, 11-1 2ths of an inch ; diameter, 4-12ths of an inch, nearly. 



Locality. — Barton. 



No. 232. Pleurotoma acutisinuata. F. E. Edwards. Tab. XXXII, fig. 5, a, b. 



P. testa elongafo-fusiformi, gracili, sub-turritd, acuminata, undique spiral/ ter Unpaid: 

 anfractibus convexiusculis, ad humeros angulatis, postice declivis, concavis ; lineis spiralibus 

 confer tis, irregular ibus : aperturd sub-quadratd, in canali brevi exeunte ; labro paululum 

 arcuato ; sinu ad humerum collocato, latissimo, minime prof undo, trigono, ad apicem acute 

 angulato. 



Shell slender, oblong-fusiform, somewhat turreted, and ornamented with con- 

 centric, raised lines, which cover the whole surface ; spire pointed, elevated, exceeding 

 the aperture in length. The whorls, seven or eight in number, are depressedly 

 convex at the sides, and sharply angulated, almost keeled, at the shoulders ; and the 

 posterior margins which slope gently backwards, are slightly channeled and girt by a 

 single raised line round the suture. The spiral lines are close-set, threadlike, equal, 



