78 MOLLUSCA FROM THE GREAT OOLITE. 
nodos sitd; ultimo anfractu ad basim angulato subnodoso; basi subconcavd, concentricé 
striata, striis tenuibus, profundis ad umbilicum minimum nullis; aperturd subpentagond. 
Shell trochiform, subturreted ; apex rather acute; whorls step-like, narrowed beneath 
the band, transversely and finely striated, coronated in the middle by a circle of nodules, 
subundulated even to the suture; the sinus is large and deep, the band of the sinus is flat, 
densely striated longitudinally, and situated beneath the nodules; the last whorl is 
angulated at lower margin and slightly nodulated; the base is somewhat concave, con- 
centrically and very delicately striated; the umbilicus is very small or obsolete; the aperture 
is nearly pentagonal. 
Locality. Two specimens only have been found in the Minchinhampton district. Both 
are small compared with the fine specimen figured by M. Deslongchamps, who is very 
fortunate in that respect, considering that the species is likewise very rare in Normandy. 
Its position is the soft shelly Oolite beneath the planking at Minchinhampton Common. 
PLEUROTOMARIA DISCOIDEA. Plate X, fig. 12. 
P. Testa turbinato-depressd, spird obtusa, anfractibus subconvexis, levibus et angustatis ; 
sinu angustissimo ; fascid sinus strictd, et planatd interdum vix notatd, infrd mediam an- 
Jractuum sitd ; ultimo anfractu ad basim angulato convexo, basi subconvend, levi ; umbilico 
minuto aut nullo, apertura subquadratd. 
Shell turbinated, depressed: spire obtuse; whorls somewhat convex, smooth, and 
narrow ; sinus very narrow; the band of the sinus narrow, flattened, and smooth, some- 
times scarcely distinguishable, and placed beneath the middle of the whorls ; the last whorl 
is angulated, and convex at the margin; the base is slightly convex, and smooth; the 
umbilicus minute or wanting; the aperture subquadrate. 
The small elevation of the spire, which is only equal to two fifths of the basal diameter, 
necessarily renders the whorls narrow ; the basal angle of the last whorl is unusually acute ; 
the sutures of the whorls are strongly marked. 
Though possessing few distinctive characters, it is little liable to be confounded with 
others ; the extreme smoothness, depressed form, and proximity of the sinus and fascia to 
the base of the whorls, are obvious and sufficient features. Height 4 lines, basal diameter 
10 lines. 
Locality. We can enumerate seven specimens; they occurred in the white stone at 
Bussage ; also in the lower portion of the formation on the south side of Minchinhampton 
Common, where the rock is not very shelly. 
