ADDENDA. J>3 



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

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

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



Gcohyical Position and Localily. The Forest Marble of I.aycock; in the collection 

 of W. Walton, Esq. 



Cerithium (?) pocuLUM, Lyc. Tab. XLIV, fig. 24. 



Testa parca, subcyliiidrica, anfractibus (9) laviyatis, postice expmsis et profunda 

 canaliculatis, antice contractis ; operticra parva, canali contracto et contorfo. 



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. 



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

 collected by E. Witchell, Esq. 



Cerithium exscalptum, Lyc. Tab. XLIV, fig. 23. 



Testa parva, subulo-elonyata, anfractibus (10) anyustis, sub-planis, transverse tenuissime 

 striatis, anfractu ultimo 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. 



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

 E. Witchell, Esq. 



KiLVERTiA, Gen. Nov. 



Testa elonyata, sub-cylindrica, anfractibus numerosis, perpendicular iter costatis tubercu- 

 latis aut spinosis ; anfractu ultimo cylindrico, basi sub-contracto ; opertura inteyra, rotun- 

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

 soli da. 



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



