GASTEROPODA. 41 



NATICA. 



Shell subglobose, thick, smooth ; spire pointed, more or less elevated, of few volutions ; 

 aperture large, oblique, ovate, entire ; columella lip oblique, thickened, the umbilicus being 

 nearly covered by a deposition of shelly matter upon the columella ; outer lip simple, 

 smooth. 



NATICA INTERMEDIA. Plate VI, figs. 1, la. 



N. Testa ovatd, spird elatd, anfractibus (5) convexis, angustis, superne planis ; averturd 

 ovato-elongatd, basi laid. 



Shell ovate, spire elevated, whorls (5) convex, narrow, flattened above ; aperture ovately 

 elongated, base wide. 



The general contour of this shell approaches nearer to Natica adducta, Phillips, than 

 any other Great Oolite species which we have examined. Its position is intermediate to 

 that species and our Natica Stricklandi, which latter species is more elongated. In all 

 these shells the upper portion of the whorls is horizontal ; but in N. adducta it is even 

 depressed as it approaches the suture, forming a narrow channel. N. intermedia is more 

 ovate, or less globose, than N. adducta. In that species the transversal is equal to the 

 longitudinal diameter ; but in N. intermedia the dimensions are as follow : Length 2 inches, 

 breadth 1 inch 7 lines. 



Locality. The planking of Minchinhampton Common has supplied the few specimens 

 we have met with. 



NATICA' GRANDIS, Gold/. Plate VI, fig. 12. 



NATICA GRANDIS, Goldfuss. Petref., iii, p. 118, t. 199, fig. 8. 

 Bronn. 1848. Index Palaeont., p. 783. 



N. Testa globoso-deprcssd, spird subexsertd, anfractibus convexiusculis, ultimo anfractu 

 ventricoso ; margine dcpresso ; aperturd semilunari ; umbilico tecto. 



Shell globose, depressed ; spire little elevated ; whorls rather convex, their margins 

 rather depressed, the last volution ventricose ; the aperture large, semilunar ; the umbilicus 

 covered by a callosity of the lip. 



We have only met with three examples of this species : two of these were obtained 

 from the upper limestone beds, the other from the planking. The general form is more 

 ventricose, and the last whorl more expanded, than either of our other species. The nearest 

 approximation to it is the Natica adducta, Phillips, of which, possibly, our shell may only 

 exhibit a more advanced stage of growth ; but as the spire of that species is more produced, 

 and as our shell perfectly agrees with the species figured by Goldfuss, we prefer, for the 

 present, to retain his designation. 



Locality. Minchinhampton. 



