352 PROF. E. FORBES ON LOWER GREENSAND FOSSILS. 



138. Cerithium turriculatum. Sp. nov. (PL iv, fig. 7 a.) 



C. testa conica, turrita, anfractibus 9 — 11, convexis, cari- 

 natis, transverse obsolete striatis, carinis nodulosis. 



Lon. 0^ ; lat. ult. anf. 0^ unc. 



Var. /3. angustive. (PI. iv. fig. 7 b.) 



Shell turreted, lanceolate, with convex whorls which are sur- 

 rounded by a spiral keel often doubled on the body whorl. This 

 keel is not so prominent as in the last species, and is nodulated. 

 The whorls are marginated at the suture. They are crossed by 

 obscure lines of growth. There are two varieties, the one branch 

 broader than the other. 



Loc. Atherfield. (Common in the Cracker bed.) 



139. Cerithium attenuatum. Sp. nov. (Pl.iv.fig.il.) 



C. testa angustissima, elongata, anfractibus numerosis, 

 carinatis spiraliter costatisque, costis omnibus nodulosis. 



Lon. Oi; lat. 0^ unc. 



A very distinct species, extremely friable and seldom found at 

 all approaching to perfect. It is extremely slender, with many 

 whorls which are spirally ribbed ; the ribs are from 5 to 7 on each 

 whorl, all nodulated, and the centre one forming a sharp and pro- 

 minent keel. 



Loc. Atherfield. 



140. Cerithium Phillipsii Leymerie, pi. 17. fig. 10. ? 



Nearly resembling the recent Cerithium Lima. The whorls 

 are encircled by 3, 4 or 5 granulated ribs, and are crossed at 

 intervals by varices. (Plate iv. fig. 12.) 



Loc. Atherfield. 



141. Cerithium Clementinum D'Orbigny, T. C. pi. 228. f. 1. ? ? 



C. testa turrita, anfractibus convexiusculis, spiraliter striatis, 

 longitudinaliter costatis, costis granulosis ; sutura impressa. 



Differs from the last in the flatness and narrowness of the 

 whorls. (Plate iv. fig. 9.) 



Loc. Atherfield. 



142. Cerithium Lallierianum D'Orbigny, T. C. pi. 229. f. 7, 8. 



A short, ventricose, 7-whorled species, spirally striated and 

 strongly ribbed longitudinally, the ribs ceasing half way down on 

 the body whorl. It agrees well with D'Orbigny's figure. His 

 species is however from the Gault. It has much the aspect of a 

 Nassa. (PI. iv. fig. 10.) 



Loc. Atherfield. (In the Cracker beds.) 



Note. Figures are given of all the Lower Greensand Cerithia, on account 

 of the difficulty in distinguishing the species from description alone. It is pro- 

 bable that several other species besides those enumerated will yet be found, 

 especially in the Cracker beds. 



