PULMONATA. 151 



of the under surface of the body-whorl, and reaching almost to the very apex of 

 the spire. 



A Volute from the lower calcaire grossier has been referred by Lamarck, and subse- 

 quently by Deshayes, to Brander's Strom, ambiguus ; the French shell, however, is quite 

 distinct, not only as to the spire, which, owing to the flattened sutural margin of the 

 whorls, has a turreted aspect, but also as to the condition of the spines, the columella, 

 and the columellar folds. Lamarck's shell is, in fact, the V. elevata of Sowerby. 

 Deshayes has also cited Brander's fig. 70 for his V. ambigua; that shell is, however, 

 equally distinct ; it is the V. suspensa of Sowerby. Lamarck's V. bicorona, for which 

 that author, as well as Deshayes, has cited Brander's fig. 69, is distinguished from this 

 species by the double row of tooth-like spines which crowns the whorls, by the shorter 

 and less conical spire, and by the smooth outer lip. 



Specimens frequently occur in the sands of Barton, in which the ribs are less nu- 

 merous, more prominent, and laterally compressed ; the tubercles assume the form 

 of erect, blunt spines : the outer lip is thin and crenulated, and, in many instances, 

 smooth within, although in others a comparatively feeble internal plication is found. 

 These specimens present a close resemblance to immature shells of V. luctatrix, and, on 

 a cursory examination, might be referred to that species. The largest of the many I 

 have seen, barely exceeds in size the individual figured (fig. 4, c), and, in all instances, 

 the conical form of the spire and the obtusely angulated condition of the whorls which 

 characterise the present species are found. I am induced, therefore, to regard these 

 shells as forming a variety of V. ambigua rather than of V. luctatrix. 



The Volute from the chalk formations of Sussex, described by Dr. Mantell, does not 

 belong to the present species to which that author referred it, and D'Orbigny (' Prod, 

 de Pal.,' vol. ii, p. 154, No. 171) has named it Pseudo- ambigua. Grateloup's shells, from 

 Dax, Gaas, and Lesbarritz, belong to Lamarck's V. ambigua, to which species they are 

 referred. 



Size. — Axis, rather more than 2 inches; diameter, 9-10ths of an inch. 



Localities. — Barton ; Alum Bay (Stratum No. 29, Prestwich). 



No. 90. Voluta digitalina. Lamar ck. Var. Lima. Sowerby. Tab. XIX, figs. 2 a — c 



Buccinum scabriculum, Sol. 1766. Brand. Foss. Hant., p. 33 ; t. 5, fig. 71. 

 Voluta digitalina, Lamk. 1811. Ann. du Mus., vol. 17, p. 77, No. 10. 



— lb. 1822. Hist. Nat., vol. vii, p. 351, No. 10. 



— lima, J. Sow. 1823. Min. Con., vol. iv, p. 136 ; t. 398, fig. 2. 



— digitalina, Defr. 1829. Diet, des Sci. nat., vol. lviii, p. 477. 



— — Desk. 1824-37. Desc. des coq. foss., vol. ii, p. 6'93 ; t. 93, figs. 1, 2. 



— lima, Morris. 1843. Cat. Brit. Foss., p. 168. 



— scabricula, If Orb. 1850. Prod de Pal., vol. ii, p. 415, No. 1468. 



— crenulata. Sow. 1850. Dixon's Geol., &c, of Sussex, t. 5, fig. 22. 



