154 GASTEROPODA OF THE INFERIOR OOLITE. 
71. Cerrraium supaspreviatum, D’Orb., 1850. Plate VIII, fig. 11. 
1850. CERITHIUM SUBABBREVIATUM, D’Orb. Prod., vol. i, p. 271. 
1842. MEnANIA AaBBREVIATA, Desi. Mem. Soe. Linn. Norm., p. 219, pl. xi, 
fig. 67. 
Bibliography, §c.—The most natural course, in this case, would be to retain the 
specific name given by Deslongchamps, by whom the species was originally described. 
But the specific term abbreviatum has already been bespoken by Mr. Leckenby 
for a Cerithiwm described by him. 
Description : 
Length . : : . . 16mm. 
Width : 5 5 . =) | Omm: 
Ratio of body-whorl to entire shell : - a0: LOO: 
Spiral angle : : S128": 
Shell ovate, turrited. Spiral angle scarcely if at all convex. Number of whorls 
about twelve; these are narrow and subtumid ; suture close and but little inclined. 
The spiral lines are very fine and numerous, and extend over the entire shell (in 
the figured specimen the faintness of this ornament is in part due to wear). The 
longitudinals are extremely numerous, extending with regularity, in the form of 
slightly arcuate coste, from suture to suture. 
Body-whorl subventricose. Aperture ovate with a considerable callus on the 
columella; canal short, small, and slightly reflexed. 
Relations and Distribution—Deslongchamps pointed out the relationship of this 
rare shell to “ M/elania scalariformis.” The shortness of the whorls of the spire 
and the ventricose character of the body-whorl constitute its principal difference. 
A single specimen from P,, Burton Bradstock. 
72. (P) CERITHIUM OBESUM, sp. nov. Plate VIII, fig. 12. 
Description : 
Length . : 5 : 3 oo arm, 
Width . ‘ : ‘ . o.mnm. 
Ratio of body-whorl to entire shell, about » 100) 100- 
Spiral angle, about A : ans DES 
Shell short, ovate, turrited. Number of whorls about six, convex, and increasing 
very rapidly. ‘The ornaments consist of three or four spirals which decussate with 
