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EOCENE MOLLUSCA. 



wider apart, being separated by spaces as wide as themselves ; they are flattened on 

 the upper surface and roughened by the lines of growth. The whorls present a series 

 of faint, almost obsolete, longitudinal, curved plications, representing the successive 

 edges of the outer lip, and which on the last whorl extend almost to the base. The 

 aperture is nearly oval, and terminates in front in a wide, short, and oblique canal ; 

 the outer lip is much arched, thin, and sharp-edged ; and the sinus, which is placed 

 on the shoulder, is very wide, deep, and almost semicircular in shape. 



Size. — Axis, nearly 6-12ths of an inch ; diameter, not quite 2-1 2ths of an inch. 



Locality. — Clarendon, where it apparently is very rare. 



No. 229. Pleurotoma Woodii. F. E. Edwards. Tab. XXXII, fig. 10, a, b. 



P. testa turriculatd, omnino concentr ice line atd : spird elevatd, acuminata : anfractibus 

 planulatis, ad humeros obtuse angulatis, et carina latissimd, rotundatd, in medio spiraliter 

 sulcata, instructis ; marginibus posticis angustissimis, depressis : lineis concentricis supra 

 partes medias et anticas anfracftium sub-distantibus, latis, depressis; supra carinam et 

 margines posticas fere obsoletis ; aperturd sub-quadratd, in canali brevi exeunte : labro 

 paruni arcuato ; sinu semicirculari, ad carinam collocato. 



Shell turreted and spirally lined, with a pointed, elevated spire, rather longer 

 than the aperture ; whorls, eight, exclusive of the pullus, nearly straight at the sides, 

 and obtusely angulated at the shoulders, where they present a very broad, prominent, 

 rounded keel, traversed along the middle by a narrow and shallow furrow, repre- 

 senting the progress of the extremity of the sinus ; the posterior margins are exceed- 

 ingly narrow, depressed, and concave, and are simple on the sutural edge. The concentric 

 lines over the middle and front parts of the whorls are rather numerous, regular, 

 band -like, depressedly convex on the upper surface, and separated by deep concave 

 furrows, equalling the bands in width ; over the keel and posterior margins the con- 

 centric lines are nearly obsolete. On the early whorls the lines of growth are very 

 perspicuous, resembling small, oblique costae ; these are lost on the last two whorls. 

 The aperture, owing to the somewhat fiat sides and the depressed posterior margin of 

 the whorls, is subquadrate in form, and terminates in front in a short, moderately wide 

 canal, rendered slightly oblique by the curve of the columella ; the outer lip is very 

 little arched, almost straight, and is smooth within ; and the sinus, which is on the 

 keel, is moderately wide and semicircular. 



This well-marked Pleurotoma is extremely rare ; I have dedicated it to Mr. Searles 

 Wood, by whom it was discovered, and to whose liberality I am indebted for the 

 specimen figured. 



Size. — Axis, 5-12ths of an inch, nearly; diameter, 2-12ths of an inch. 

 Locality. — Headon Hill. 



