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EOCENE MOLLUSCA. 



No. 220. Pleurotoma obscurata. Sowerby. Tab. XXXI, fig. I, a, 6. 



Pleurotoma obscurata. Sow. 1850. Dixon's Geol., &c, of Sussex, p. 184, t. 7, fig. 19. 

 — — Morris. 1854. Cat. Brit. Foss., p. 270. 



P. testa angustd, turritd, omnino concentrice lineatd, undulato-costatd : spird elevatd: 

 anfractibus namerosis, convexiusculis ; postice canaliculatis, ad suturam unicd serie tuber- 

 culorum cinctis ; antice coarctatis ; lineis concentricis crebris, exilibus, regularibus ; costis 

 numerosis, brevibus, curvis, ad humeros prce-eminentibus ■• aperturd ovali, in canali brevi, 

 paullulo rejlexo, exennti ; labro aliformi, ad humerum anguste et profunde sinuato ; 

 columella sub-recta. 



A long, narrow, turreted shell, ornamented with numerous curved ribs, and 

 having the whole surface covered with raised, spiral lines ; the spire, which is formed 

 of ten or eleven volutions, exclusive of the pullus, is much elevated, forming 3-5ths of 

 the entire length of the shell ; the whorls are flatly convex, and much contracted in 

 front ; and the posterior margins are slightly channeled, and thickened round the suture, 

 where they present a single row of oblique, oblong tubercles. The ribs are numerous, 

 short, and curved, following the outline of the outer lip ; they are thick, rounded, 

 and prominent on the shoulders, imparting somewhat of a turreted character to 

 the spire, and they taper rapidly as they cross the middle of the whorls, where they 

 are lost ; the spiral, raised lines are thread-like, numerous, and irregular. The 

 aperture is of a roundish-oval form, and terminates in front in a short, but distinct, 

 rather wide, and nearly straight canal, having the anterior extremity slightly bent 

 backwards ; the outer lip is curved, wing-shaped, with the front part much pro- 

 jecting ; the sinus, which is placed on the shoulder, is of a narrow, deep, oblong 

 form ; the columella nearly straight, and crested by the reflexure of the canal. 



Size. — Axis, 1 inch and 3-12ths; diameter, rather more than 10-12ths of an 

 inch. 



Locality. — Bracklesham Bay. 



No. 221. Pleurotoma lima. F. B. Edwards. Tab. XXXII, fig. 3, a—c. 



P. testa elongatd, sub-turrild, longitudinaliter curvo-plicatd, concentrice scabro-lineatd, 

 lidjercidato-carinatd : spird elatd, obtusd : anfractibus planulatis, ad humeros angulatis ; 

 postice concavis, ad suturam granulatis ; ultimo anfractu brevi, antice coarctato, in canali 

 brevi obliquo, terminato ; plicis longitudiiialibus numerosis, acutis, ad basin tendentibus ; 



