52 MOLLUSCA FROM THE GREAT OOLITE. 
Family—LitTToRINIDz&. 
Rissoina, D’ Orbigny. 1842. 
Shell turreted, acuminated; spire long, consisting of several whorls; aperture oval, 
rather pointed at the two extremities; outer lip thickened, emarginated; columella 
rounded, straight. 
Rissomna DupLicata, Sow. Plate IX, fig. 10. 
Rissoa Dupiticata, Sow. 1829. Min. Con., t. 609, fig. 4. 
— — Brown. Ilust. Foss. Conch., t. 38, figs. 14, 15. 
— Morris, Cat. Brit. Fossils, p. 161. 
— — Bronn, Index Palont., p. 1092. 
Rissorna DupLicata, D’Orb. Prod. Paléont., p. 297. 
oo — D'Orb. Pal. Frang. Terr. Jurass., t. 237, figs. 1, 2. 
A. Testéd parva turritd, acuta; anfractibus (6) in medio angulatis ; costulis longi- 
tudinalibus angustatis, remotiusculis ; carind unica in medio anfractuum sitd ; anfractu 
ultimo, costulis numerosis longitudinalibus rectis ornato, carina evanescente. 
Shell small, turreted, acute; whorls (6) angulated, with remote, narrow, longitudinal 
coste ; each whorl has a low carina, situated a little beneath its middle part; the last 
whorl has very numerous small, longitudimal and straight ribs; the carina is scarcely dis- 
cernible upon the last whorl. The costa upon the last whorl are twice as numerous as 
upon the spire, and the figure of the whorl is nearly cylindrical, or slightly biangulated ; 
and the carina becomes obsolete; the 2ssoa unicarina of Buvignier, and the Fusus cari- 
natus of Roémer, approach very nearly to this species, with which they may possibly 
be identical ; judging from the descriptions, however, there are certain points of distinction 
which appear to separate them from our species. Length 2 lines. 
Locality. Ancliff and Minchinhampton Common ; at the latter place it is very rare, 
and found only in the beds of planking. 
Rissoina opiievata, Sow. Plate IX, fig. 19. 
Rissoa OBLIQuATA, Sow. 1829 Min. Con., t. 609, fig. 3. 
_— — Brown. Must. Foss. Conch., p. 79, t. 38, figs. 19, 20. 
— -- Bronn. Index Palzeont., p. 1093. 
Rissorna OBLIQUATA, D’Orb. Prod. Paléont., p. 297. 
R. Testa turritd, turbinatd, acutd ; anfractibus (6—7) convexis et costatis; costs a 
dextro ad sinistram obliquis. 
