32 MOLLUSCA FROM THE GREAT OOLITE. 



Cerithium tennanti. Plate IX, fig. 20. 



C. Testa turritd, acuta, conicd, anfractihus numerosis, angustatis, tricinctis ; carinis 

 tribus, elalioribus, striis numerosis longitudinalibus impressis ; basi planatd, canali 

 brevissimd. 



Shell turreted, acute, conical, whorls numerous, thrice cinctured ; the bands elevated, 

 and impressed with numerous longitudinal striae ; base flattened, canal obsolete. 



The transverse keels are equal, narrow, and elevated, one being mesial, the others close 

 to the anterior margin of the whorls ; the figure is perfectly regular, and the whorls 

 narrow ; the aperture and canal are very short. 



Locality. Ancliff. 



Named after Prof. J. Tennant, from whose interesting collection of Oolite Fossils this 

 species is figured. 



Cerithium Roissii, Arch. sp. Plate VII, fig. 14, 14«. 



Turritella Roissii, Archiac. 1843. Mem. Soc. Geol. Fr., vol. v, p. 380, t. 30, f. 2. 



— — Bronn. Index Palseont., p. 1336. 



Chemnitzia Roissyi, If Orb. Prod. Paleont., p. 298. 



C. Testa turritd subconicd, lavi, apice acuto ; anfractibus paucis, planatis; suturis vix 

 tumidulis; caudd brevi subrectd. 



Shell turreted, subcorneal, smooth; apex acute; whorls few, flattened; the sutures slightly 

 tumid ; canal short, and nearly straight. 



A very short or conical species, the diameter of which through the last whorl is upwards 

 of half the entire length of the shell ; a longitudinal section displays a columella of great 

 thickness, the internal cavity being small. 



Locality. Rare in the Great Oolite of Minchinhampton Common. Eparcy, France. 



NerinjEA, Def ranee. 1825. 



Shell turreted, either conical or cylindrical, consisting of numerous whorls ; aperture 

 subquadrate, having an anterior and posterior short canal ; columella, with one or more 

 folds ; outer lip, with one or more folds, which are continued through the length of the 

 shell ; columella umbilicated in the conical, solid in the cylindrical species. 



Nerin.&a Voltzii, Desl. Plate VII, figs. 11, 11a ; var? figs. 7, la. 



Nerin^ea Voltzii, Deslongchamps. 1842. Mem. Soc. Linn. Normandie, vol. vii, pi. 8, 

 fig. 34. 

 _ _ If Orb. Prod. Paleont., p. 298. (Not N. Voltzii, D'Arch.) 



