ADDENDA. 93 



Shell small, turreted, volutions numerous (8 9), narrow, inflated, the sutures deeply 

 impressed; costae (about 11 in the circumference) perpendicular and narrow, crossed by 

 a few regular encircling lines. The aperture and canal are imperfect. 



Geological Position and Locality. The Forest Marble of Laycock ; in the collection 

 of W. Walton, Esq. 



CERITHIUM (?) POCCLUM, Lye. Tab. XLIV, fig. 24. 



Testa jyarva, subcylindrica, anfractibus (9) l&vigatis, postice expamis et profunda 

 canaliculatis, antice contractis ; apertura parva, canali contracto et contorto. 



Shell small, subulate, subcylindrical, volutions (about 9) smooth, expanded posteriorly 

 and deeply channelled, contracted anteriorly, the aperture is small, the canal is produced , 

 narrow, and twisted. 



The genus is somewhat doubtful, additional specimens may prove it to be a Nerinaa. 



Geological Position and Locality. The Great Oolite of Bussage, near Bisley Common ; 

 collected by E. Witchell, Esq. 



CERITHIUM EXSCALPTUM, Lye. Tab. XLIV, fig. 23. 



Testa parva, subulo-elongata, anfractibus (10) angustis, sub-planis, transverse tenuissime 

 striatis, anfractu ulfimo rotundo, canali brevi, sub-recto. 



Shell small, subulately turreted, pointed, volutions (10) slightly convex, narrow (two 

 and a half times as wide as high), with numerous very delicate encircling striations, the 

 last volution has the base rounded, the canal is short and nearly slight. 



Obtained by crushing the white stone for the Great Oolite for minute Gasteropoda. 



Geological Position and Locality. The Great Oolite of Bussage; collected by 

 E. Witchell, Esq. 



KILVERTIA, Gen. Nov. 



Testa elongata, sub-cylindrica, anfractibus numcrosis, perpendiculariter costatis tubercu- 

 latis aut spinosis ; anfractu ultimo cylindrico, basi sub-contracto ; apertura Integra, rotun- 

 data aut ovali, labris protractis, tenuiter incrassatis, non nunquam sub-undulatis, cotumetta 

 solida. 



Shell elongated, sub-cylindrical, sometimes somewhat pupaeform ; volutions numerous, 



