GASTEROPODA. 63 



angle, and not immediately at the suture. The transverse striae are continued over 

 the ribs when the shell is perfect, but those prominent parts are often smooth. The 

 costse are in general vertical, though in some there is a slight curvature. The speci- 

 mens from Bramerton appear punctated, from an alteration and erosion of the surface. 

 A specimen from Bridlington, sent by Mr. Bean, with the name "plicatiZis" appears to 

 be a variety of this species, which is very variable in its proportionate dimensions as 

 well in the fossil as in the recent specimens ; several shells, considered as specifically 

 distinct by Moller, are probably only varieties. 



13. CLAVATULA TREVELLIANA. Turt. Tab. 7, fig. 14. 



PLEUROTOMA TRAVELLIANA. Turt. Mag. Nat. Hist. p. 351, 1834. 



Thorpe. Brit. Mar. Conch, p. 197, fig. 52, 1844. 



Macgyllivray. Moll. Aberd. p. 172. 

 fusus (?) TURRICULA, var. S. Wood. Catalogue 1842. 



Cl. Testa ovato-fusiformi, spird subturritd; apice acuto ; anfractibus 5 6, convexis, 

 subinjlatis, superne angulatis ; longitudinaliter costulatis, costulis confertis; transversim 

 rugose striatis, cancellatis ; aperturd ovatd, canali brevissimd. 



Shell ovato-fusiform, with a slightly elevated spire, and acute apex ; whorls 5 6, 

 convex and rather tumid, angulated at the upper part ; longitudinally costulated with 

 numerous rather oblique and slightly prominent ribs, and large transverse stride 

 decussating and cancellating the exterior. 



Axis, \ an inch. 



Locality. Red Crag, Sutton. 



Mam. Crag, Bramerton. Recent, British Seas. 



This shell appears to correspond with the figure and description of what is con- 

 sidered a distinct species, and I have given it upon the authority of British conchologists, 

 who may perhaps have better means of determining that point either from colour or 

 other character. I have but two or three specimens ; it may, however, be a variety 

 of Cl. turricula, as it is only in the proportions that I can observe any difference between 

 my fossil specimens of this species and those of turricula. 



14. CLAVATULA BOOTHII. Smith. Tab. VII, fig. 16. 



PLEUROTOMA PURPUREA. Bast. Mem. Gol. de Bord, pi. 3. fig. 10, 1825. 

 Fusus BOOTHII. Smith. Wern. Mem. vol. viii, p. 51, pi. 1, fig. 1, 1838. 



CL Testa fusif or mi, turritd, longitudinaliter costatd ; anfractibus converts, transversim 

 lineatis, lineis elevatis ; labro obtuso, intus nitido ; canali brevi subrectd. 



Shell turreted and fusiform, longitudinally costated ; whorls convex, slightly inflated, 

 covered with elevated striae ; outer lip obtuse, smooth within ; canal short, and slightly 

 recurved. 



Axis, | of an inch. 



Locality. Red Crag, Walton Naze. Recent, British Seas. 



