GASTEROPODA. 75 



American Miocene fossil by Mr. Lyell. The striae or ridges are rather irregular, 

 though generally there is one large and one small one alternately ; they are all sharp 

 and angular. The ridges upon recent specimens are also irregular in their disposition, 

 having sometimes fine transverse striae between them. Fig. 9 b is from the Red Crag, 

 resembling the general form of the recent shell. Fig 9 a is from the Mammaliferous 

 Crag at Thorpe, which I presume to be the same species, although it is more 

 subulate in form, with a deeper suture, and more convex volutions. 



2. TURRITELLA IMBRICATARIA. Lam. Tab. IX, fig. 10, a b. 



TURRITELLA IMBRICATARIA. Lam. An. du Mus. vol. iv, p. 216, pi. 37, fig. 7, 1804. 



Desk. Coq. foss. des Env. de Par. pi. 35, fig. 1-2, and pi. 37, fig. 9-10. 

 Nyst. Coq. foss. de Belg. p. 397, pi. 37, fig. 5. 



TURRITELLA coNOiDEA. J. Sow. Min. Conch, t. 51, fig. 145, 1814. 

 S. Wood. Catalogue 1842. 



T. Testa, elongato-turritd, subulatd ; anfractibusplanatis, ad basim subangulatis, trans- 

 versim striatis, striis imbricatis, vel subtilissime granulatis. 



Shell elongate, turreted, and tapering, with flattened volutions, slightly angulated at 

 the lower part ; transversely striated with imbricated or finely-granulated striae. 



Axis, 2 inches. 



Locality. Red Crag, Sutton and Newbourn. 



My cabinet contains about thirty specimens of this shell, which is no doubt the same 

 species as the one so abundant in the Eocene formation, at Barton ; my specimens are all 

 more or less rubbed, and may probably be a diluvial introduction from the older bed, 

 although that number is rather large for such a casualty. One specimen is covered 

 with fine and regular transverse striae, which though rubbed show the remains of 

 granulations ; the angular form of the base of the volution appears to be its distinguishing 

 character. Fig. 10 b is from a specimen much worn and eroded, and exhibits a more 

 conical form of volution than the generality of these shells. 



3. TURRITELLA INCRASSATA. J Sow. Tab. IX, fig. 7, a d. 



TURRITELLA INCRASSATA. J. Sow. Mm. Conch, t. 51, fig. 6, 1814. 

 TURBO TRIPLICATES. Brocchi. Foss. Subapenn. t. 6, fig. 14, 1814. 



DUPLICATES (?). - t. 6, fig. 18. 



IMBRICATARIUS. - t. 6, fig. 12. 



VERMICULARIS. t. 6, fig. 13. 



TURRITELLA DUPLICATA. Dubois de Montp. Conch, foss. Wolhyn. Podol. pi. 2, fig. 19-20, 1831. 

 TRIPLICATA. Dujard. Me"m. Soc. Geol. de France, torn, ii, pt. 2, p. 287, 1837. 



Grateloup. Foss. de Dax (Actes de la Soc. Linn, de Bord.), torn, v, 



p. 161, 1838. 



Nyst. Coq. foss. de Belg. pi. 37, fig. 7-8, 1844. 

 INCRASSATA. S. Wood. Catalogue 1842. 

 BICINCTA. - var. /3, fig. 7 d. 



T. Testa turritd, anfractibm planulatis ; transversim striatis, cingidos duos vel tres 

 obtusos distantes ferentibus ; cingulo intermedia crassiore, supremo obsoleto. 



