128 
Nerinza Guiser. Pl. IV, fig. 2. 
Shell slender, sub-cylindrical, volutions very numerous, much 
excavated, encircled with minute costz, irregular and unequal, 
eight to ten to a volution, suture prominent, acutely carinated, 
columella solid, with one fold, outer wall with two folds near 
the middle of the volution; aperture unknown. 
Fragments of this shell—and it has only been found in a 
fragmentary condition—indicate that it was of considerable 
length, not less than 9 inches. 
The costee and internal folds are observable only on the better 
preserved shells. The first costa is close to the suture, and is 
more prominent than the others, giving to the edge of the suture 
a furrowed appearance: the other coste, except the three last, 
are rather wide apart, but these three are close together. Indi- 
cations of a second fold on the columella, corresponding with 
the posterior fold on the outer wall are sometimes observable. 
The prominence of the sutures, the great concavity of the 
whorls, the arrangement of the costz, together with the internal 
folds, sufficiently distinguish this from other lengthened slender 
Species; but, owing to the fragmentary condition of all the 
specimens, we are unable to compare sufficiently the volutions 
of the young form with those of the adult condition, and are 
therefore unable to judge of the figure of the entire shell. 
Locality and position—the Clypeus Grit of Rodborovgh Hill. 
Common. 
Trocuus Cuypratus. PI. IV, fig. 3. 
Shell small turbinated, whorls angulated, encircled with a 
prominent rib near the suture, giving the shell a step-like 
appearance. Thereare two other small ribs on the side. The 
last whorl has three acute ribs nearly equidistant, two of which 
form the upper and lower angles of the whorl; all the angles 
are acute. Base smooth, entire; aperture nearly round. 
This shell is sufficiently distinguished from other species by its 
turbinated form andthe angularity of the whorls. Height, 5 lines. 
Geological position and _ locality,—the Clypeus Grit of 
Rodborough Hill, where it is abundant. 
