GASTEROPODA. 



RISSOA? EXIGUA, Lyc. 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 simplici. 



Shell small, ovately conical; spire consisting of six flattened or slightly convex, narrow- 

 volutions, the sutures being strongly marked ; longitudinal costae 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. 



CERITHIUM? SPICDLDM, Lyc. Tab. XLIV, fig. 1. 



Testa ovato-elongata, minuta, anfractibus (6) latis subplanis, transversim striatis etlon- 

 gitudinaliter costatis ; costis rectis (Qin 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 in a volution j the last 

 volution is nearly cylindrical ; the aperture is small, ovate ; there is no canal. 



The costae, 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 pupaeform ; the general figure approximates to C. strangulatum, but more lengthened, 

 and with higher volutions. 

 , Geological Position and Locality. The Great Oolite of Minchinhampton. 



CERITHIUM ? COMPOSITUM, 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 costae 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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