478 GASTEROPODA OF THE INFERIOR OOLITE. 



Genus — Cylindrites, Morris and Lijcett, 1851. 



*' Shell smooth, snh-cylindrical, or ovate; spire small; tvhorls usually flattened, 

 with acute margins, the last ivhorl cylindrical, aperture lengthened, linear above, rounded 

 and entire at the base ; columella rounded, tioisted near to the base and slightly directed 

 outwards ; right lip thin, but thicker at the base.^^ — Morris and Lycett. 



This is chiefly a genus of the Great Oolite ; the number of species in the 

 Inferior Oolite is limited, and their distribution very partial. Considerable 

 difiBculty arises from the uncertain evidence with regard to the identification of 

 Lycett's species from the Inferior Oolite of Gloucestershire. On the whole the 

 species of Cylindrites may stand thus : 



Turrited .... Cy. turriculatus, Lycett. 



. . {^U- attemiaf.us, Lycett. 



Spire consisting oi a low cone • -! ^v 7 • • 



\_Vy. brevispira, sp. nov. 



r(7y. tabulatus, Lycett. 

 — var. Weldonis. 

 ^Cy. mammillaris, Lycett. 



Spire sunken . . • Gif- cylindricus, Morris and Lycett. 



Spire flat or subdepressed, with a mam- 

 millary knob 



428. Cylindrites turriculatus, Lycett, 1863. Plate XLIII, fig. 12. 



1853. CviiiNDHiTES TURRICULATUS, Lycett. Quart. Journ. Geol. Soc, vol. ix, 



p. 3i2, pi. xiv, fig. 8. 



1863. — — — Great Ool. Moll., Suppl., p. 25, 



pi. xliv, fig. 26. 



Description. — "Shell elongated, subcylindrical ; spire lengthened, its apex 

 acute; whorls convex, their sutures deeply excavated, the last whorl ovately 

 cylindrical ; aperture narrow." Lycett's type is not available, nor have I seen a 

 specimen so large as the one figured by him. My specimen (fig. 12) has a spiral 

 angle of 60°, and no more than six whorls ; the spire is nearly one third of the 

 total height. 



Relations and Distribution. — Probably only a small variety of Gi/lindrites altits, 

 Morris and Lycett, from the Great Oolite, but less cylindrical, and with the 

 posterior edge of the whorls less flattened. Rare in the Lincolnshire Limestone 

 at Ponton and Weldon, it is the only species of Cylindrites from the Inferior 

 Oolite which has a well-developed spire. 



