50 MOLLUSCA FROM THE GREAT OOLITE. 



In this large species the volutions are high and globose, the base of the shell is rather 

 contracted. 



Locality. The few specimens found, have been obtained from the planking ; the fine 

 example figured is from the hard weatherstone of Bisley Common. 



Chemnitzia Hamptonensis. Plate VII, figs. 1, la. 



C. Testa elougato-conicd, spird mediocriter obtusd; anfractibus (10 — 11) plants et 

 costatis; costis longitudinalibus (20 — 22) numerosis, rectis, vel subflexuosis ; aperturd parvd, 

 eUipticd. 



Shell conical, but much elongated j spire, with the apex, somewhat obtuse ; whorls 

 (10 — 11) flattened and costated; costse numerous, perpendicular, but slightly bent in the 

 middle, inclining from left to right ; aperture small, and elliptical. 



The whorls are narrow, their axis being equal only to half their transverse diameter ; 

 the costae are narrow, and moderately elevated in young specimens, but after seven 

 volutions have been formed, became much more faintly marked, and finally are obsolete ; 

 the less subulate form and very narrow whorls separate it from Terebra vetusta (Phil. Geol. 

 York., t. 9, f. 11), to which the markings upon its surface have a near resemblance. 

 Axis of largest specimen 1 5 lines ; transverse diameter 5 lines. 



Locality. Minchinhampton Common and vicinity, where it is moderately rare : it is 

 usually found in the soft oolite beneath the planking. 



Chemnitzia Leckenbyi. Plate VII, fig. 4. 



C. Testa parvd, laevigata, subulatd ; anfractibus numerosis, subplanis, superne convexis, 

 anfractu ultimo symmetrico. 



Shell small, smooth, subulate, acute ; whorls numerous, narrow, flattened, except upon 

 their upper portions, where they are convex ; the last whorl symmetrical. 



This small species approaches in figure two contemporaneous species, viz., the young 

 state of Nerincea Voltzii and of Etrfima? communis; from the former of these it is dis- 

 tinguished by the greater flatness of the whorls; from the young state of the latter by the 

 much greater number of whorls, more subulate form, and acute apex. Axis 3^ lines. 



Locality. Minchinhampton Common. 



Chemnitzia wetherellii. Plate VII, figs. 5, ba. 



C. Testa cylindrico-elongata ; anfractibus numerosis (12) subconvexis, longitudinal d(r 

 costatis ; costis (14) rectis obtusis ; aperturd parvd, ovatd. 



Shell cylindrical, elongated, whorls numerous (about 12), somewhat convex, longi- 

 tudinally costated; costse perpendicular, obtuse, closely arranged, about 14 in a volution ; 

 aperture small, ovate. 



