129 
Nermv#a Unpurata. PI.IV, figs: 4 and 4a. 
Shell long, taper; whorls concave, but depressed and flattened 
near the sutures, giving to the profile the appearance of a series 
of undulations, costated, having four to five coste on the larger 
part, and three to four on the smaller part of each whorl. 
Aperture unknown. 
As only a fragment of this shell has been discovered, and 
being in a crystalline condition, its internal character cannot 
be ascertained. It is provisionally referred to the genus 
Nerinea. Length of fragment one inch. It contains 8 
whorls; diameter of the last whorl one eighth of an inch. 
Locality,—Clypeus Grit, Rodborough Hill. 
Triconra Gemmata. Var. bifera, Lixyc. PI. IV, fig. 5. 
This shell is described by Dr. Lycrrt, in a foot-note in his 
Monograph of the British fossil Trigomie, p. 239, thus :— 
“Tt has seven rows of concentric cost, which occupy more 
than half the height of the valve. The oblique or perpendicular 
coste, nine in number, have three only which originate at the 
marginal carina; all the others proceed from the last formed 
concentric costa to the pallial border: the general figure is 
somewhat shorter than the typical form.” No figure is given 
in the Monograph, the shell having been discovered after the 
plates were completed. Height 6 lines, length 7 lines. 
Locality,—the Clypeus Grit, Rodborough Hill. Rare. 
Crrrina Lucyr. PI. IV, fig. 6. 
Shell ovately transverse, tumid, inequilateral, umbones rather 
small, not prominent, antero-mesial, hinge border slightly 
curved, lunule excavated, base regularly elliptically curved. 
The surface of this shell exhibits faint but regular concentric 
folds of growth, with indications of concentric strie. Height 
22 lines, length 2 inches. 
Position and locality,—the Clypeus Grit of Rodborough Hill. 
Astartse ciypEatTa. PI. IV, fig. 7. 
Shell ovately subtrigonal, sub-equilateral, moderately curved, 
anterior and posterior borders nearly straight, sharply rounded 
at their lower extremities, transverse diameter slightly greater 
