170 EOCENE MOLLUSCA. 



rising at the shoulder into obtuse laterally compressed tubercles ; the transverse strise 

 are lost on the middle and front parts of the last whorl, and are only faintly traceable 

 towards the sutural margin. The aperture is elongated, narrow, with nearly parallel 

 margins ; the outer lip simple, sharp-edged, angular at the posterior extremity, 

 smooth within ; inner lip narrow ; the columella is nearly straight, and, according to 

 M. Deshayes, is furnished with three folds, of which one only is visible in front, but 

 the other two are seen when the outer lip is broken. 



The much-varying forms of V. muricina, suggested to M. Deshayes the probability 

 that this might eventually prove to be merely a narrow variety of that species, to 

 which in fact it bears a very strong resemKance : the transverse striation is common 

 to both species, and much value, cannot, I think, be attributed to the greater or less 

 number of the feeble posterior columellar folds. I should be strongly inclined, there- 

 fore, to regard this as a variety of V. muricina, were it not for the difference in the 

 size of the pullus, which, in V. angusta, is much smaller than in V. muricina ; and, as it 

 is uncertain how far external conditions may influence the development of the shell in 

 embryo, I have retained the species. 



The shell represented in Mr. Dixon's work, t. 7, fig. 37, does not, in my opinion, 

 belong to this species ; for the pullus, though small, is obtuse, not conical and pointed ; 

 and the notch is very deep : it is, I think, a large specimen of V. uniplicata. 



Size. — Axis, 3 inches nearly; diameter, 9-lOths of an inch. 



Localities. — Bracklesham Bay. French : Retheuil, Soissons, Cuise-Lamotte, 

 (fide Desh.) 



No. 109. Voluta costata. Solander. Tab. XXII, figs. 5 a — d. 



Voluta costata, Soland. 1/66. Brand. Foss. Hant., p. 24 ; t. 3, iig. 45. 



— Sow. 1821. Min. Con., vol. iii, p. 163; t. 290, figs. 1 (non figs. 2 and 4). 

 Nee — — Grat. 1847. Conchyl. foss., &c. del'Adour ; Supp. t. 1, fig. 14a— b. 



nee — — Sow. 1850. Dixon's Geol. &c., of Suss., p. 107 ; t. 5, fig. 24. 



V. testa ovato-fusiformi, costata, lineis transversis ornatd; spird elevatd, conicd ; 

 apice acuto .• anfractibus convexiusculis ; costis angustis inermibus ; apcrturd oblongo-ovali, 

 ad basin sub-profunde emarginatd ; labro simplici, tenui ; labio angusto ; columella sub-recta, 

 quadri-plica td. 



Shell ovately fusiform, longitudinally ribbed and ornamented with numerous trans- 

 verse raised lines ; spire conical, elevated, being as long or nearly as long as the 

 aperture, and terminating in a small pointed pullus ; whorls six or seven, exclusive of 

 the pullus, and rather convex ; the ribs simple, narrow, sharp, slightly curved and 

 extending to the base, numerous on the early whorls, but becoming more distant as the 

 shell is enlarged. The transverse lines, which are decussated by the lines of growth, 

 are very slender, and irregular ; every third or fourth line being thicker and more 



