156 EOCENE MOLLUSCA. 



apice acuto .■ anfractibus ventricosis, bind serie spinarum armatis ; spatio inter series con- 

 cavo : aperturd ovato-elongatd, in medio effusd, antice parum coarctatd ; labro tenui, simplici ; 

 labio expanso, postice incrassato ; columella leviter arcuatd, bis vel ter plicatd. 



Shell oblong, ventricose, longitudinally ribbed, transversely furrowed; spire 

 moderately elevated, with a small pointed apex; the ribs, which are more or less 

 numerous in different specimens, extend over nearly the whole length of the whorls, and 

 terminate posteriorly in a row of erect, sharp spines. Close to the edges of the whorls 

 rises a second row of smaller spines, the space between it and the suture forming a 

 channel round the spire more or less deep, according to the height of the spines. The 

 two rows of spines are connected by raised lines, and the intermediate space is concave- 

 On the last whorl or two of the fully formed shell, the second row of spines frequently 

 becomes obsolete, and is replaced by a sharp, elevated ridge. The furrows, in young spe- 

 cimens, extend over the whole surface of the whorl, but, as the shell advances towards 

 maturity, the posterior ones become faint, and at length are frequently almost obli- 

 terated. The mouth is contracted in front, effuse near the middle, and deeply notched 

 at the base. The outer lip is in all stages of growth thin, sharp-edged, and quite 

 smooth within ; the columellar lip is moderately spread out over the body whorls, and 

 thickened behind, and does not extend backwards beyond the suture. The columella, 

 which is slightly arched, presents in the young state, two unequal, not very oblique 

 plaits, in front of which a third obscure plait generally appears at maturity. 



Brander's shell (fig. 65), referred by Solander to V. luctatrix, and by Lamarck to 

 V. spinosa, presents nevertheless characters sufficiently distinct to entitle it, as Mr. 

 Sowerby long ago suggested, to be considered as belonging to a separate species. In 

 addition to the distinction afforded by the rows of spines, which are more equal 

 and more permanent in this species than usual, it will be seen, on comparison with 

 V. luctatrix, that in V. Solandri the shell is shorter and broader, the spire not so much 

 elevated, the outer lip always sharp edged, and without plication, the inner lip 

 not so effuse, the columella arched, and the columellar folds neither so numerous nor 

 so large ; and, on a comparison with V. spinosa, that the shell is not so turbinate, the 

 spire more elevated, and the whorls more ventricose. 



Size. — Axis, 2 inches nearly ; diameter, rather more than 1 inch. 



Locality. — Barton. 



No. 94. Voluta scalaris. Sowerby. Tab. XX, figs. 5 a — c. 



Voluta scalaris, Sow. 1843. Min. Con., vol. vii, p. 32 ; t. 625, fig. 4 — 5. 



V. testa ovatd, ventricosd, antice atlenuatd ; spird elevatd, apice acuminato : anfractibus 

 costatis, bind serie spinarum coronatis, transversim sulcatis, ad margines suturales depressis, 

 inter series spinarum concavis ; costis numerosis ; sulcis sub-distantibus, aqualibus .• labro 

 simplici, acuto; labio parum expanso ; columella sub-recta, triplicatd. 



