102 MOLLUSCA FROM THE GREAT OOLITE. 



B. Pyriformi. 

 Cylindrites bullatus. Plate VIII, figs. 18, ISa, b, c. 



? Conus? minimus, Archiac. 1843. Mem Soc. Geol. de France, torn, v, t. 30, fig. 9. 

 Action minimus, If Orb. 1850. Prod. Paleont., p. 299. 

 Act.eonella minima, Bronn. 1848. Index Palseont., p. 13. 



C. Testa subcylindricd, vel ovatd; spird depressd, inversd; apice mammittato ; anfractibus 

 numcrosis, marginibus rotundatis ; anf radii ultimo, subconvexo, basi contracts. 



Shell subcylindrical, ovate, or bullaeform ; spire depressed, inversed ; apex mam- 

 millated ; whorls numerous, with rounded margins ; the last whorl somewhat convex, with 

 a contracted base. 



This form is much shorter than the last, and less flattened j the apex of the spire does 

 not rise higher than the margin of the last whorl ; it is mammillated, and consists of three 

 minute volutions; the vertex is moderately large and crateriform. This species is very rare, 

 and has only been observed in the " planking." 



Locality. Minchinhampton Common. Aubenton, France. 



Cylindrites pyriformis. Plate VIII, figs. 20, 20a, b, c; 21. 



C. Testa cylindro-pyriformi, cava apiciali contractu profunda, margine acuto elevato; 

 aperturd ad basim vix dilatatd, plicis magnis. 



Shell cylindrical or pyriform ; the apicial cavity contracted and deeply excavated, 

 having an acute and somewhat elevated margin; aperture linear; the folds on the 

 columella large. 



This shell is more pyriform than its congeners, the anterior extremity being short but 

 attenuated, and the apicial cavity deep and contracted. The cast (fig. 21) has not the 

 produced acute margin to the cavity exhibited by the shell (fig. 20), the cavity consequently 

 appears smaller ; the apex of the spire is large but deeply situated. 



Axis 7 lines, greatest transverse diameter 4^ lines, diameter of the cavity 1| lines. 



Locality. The planking of Minchinhampton Common. Casts of this shell occur higher 

 in the series in shelly hard sandstone one mile east of Minchinhampton ; in both positions 

 it is rare. 



Act^eonina, jyOrbigny, 1850. 



COCHLITES CYLINDROIDES, Luid. 1760. 



Action, sp., Phillips. Action, sp., Sow. 

 Utriculus? Brown. 1845. Elements of Fossil Conch. 

 — Brown. 1849. Illustrations of Fossil Conch. 



