GASTEROPODA. 9 
RissoaP Exicua, Zyc. Tab. XLIV, fig. 11. 
Testa parva, ovato-conica, spira anfractibus (6) plano-convexis, angustis, suturis valde 
impressis, costis longitudinalibus rectis, angustis, 8—9 in ambitu; apertura, parva, sub- 
orbiculari, labro externo simplict. 
Shell small, ovately conical; spire consisting of six flattened or slightly convex, narrow 
volutions, the sutures being strongly marked ; longitudinal coste elevated, narrow, per- 
pendicular, 8 to 9 in a volution; aperture small, suborbicular, outer lip simple. 
A minute lenticular shell, with about eight and a half costal spaces to a volution, the 
height of each volution being equal to the half of its transverse diameter; the apex is 
slightly obtuse, and the last volution is somewhat contracted. 
Geological Position and Locality. The Great Oolite of Bussage, collected by Mr. 
Witchell. 
CeritHiumM? spicuLum, Lye. Tab. XLIV, fig. 1. 
Testa ovato-elongata, minuta, anfractibus (6) latis subplanis, transversim striatis et lon- 
gitudinaliter costatis ; costis rectis (6 in ambitu), anfractu ultimo cylindrico, apertura parva, 
ovata, canali nullo. 
Shell minute, ovately elongated subcylindrical; volutions (6) wide, rather flattened, 
transversely striated, and longitudinally costated ; costae straight, six im a volution ; the last 
volution is nearly cylindrical; the aperture is small, ovate; there is no canal. 
The costz, which have little prominence, appear to stretch continuously ; the length of 
the shell only slightly interrupted by the sutures, which are not strongly marked ; the aper- 
ture is pupzeform ; the general figure approximates to C. strangul/atum, but more lengthened, 
and with higher volutions. 
Geological Position and Locality. The Great Oolite of Minchinhampton. 
Crritnium? composirum, Lyc. Tab. XLIV, fig. 9. 
Testa parva, elongato-conica, anfractibus (6) angustis subplanis, transverse striatis et 
costatis ; scilicet anfractu ultimo et penultimo costis crebris longitudinalibus rectis, circa 
18 in ambitu; apertura parva, obliqua, ovata, depressa. 
Shell minute, conical, elongated ; volutions (6) narrow, flattened, transversely striated, 
and longitudinally costated ; but the cost are limited to the two or three latter volutions, 
they are closely arranged, little elevated, and about eighteen in a volution; the aperture is 
depressed, oblique, and ovate. 
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