42 MOLLUSCA FROM THE GREAT OOLITE. 



Natica Stricklandi. Plate XI, figs. 24, 24#. 



N. Testa ovatd, spird data, anfractibus convexiusculis, sup erne rotundatis, suturis sub- 

 depressis ; aperturd oblique ovatd ; basi angustatd. 



Shell ovate, spire elevated, whorls rather convex, rounded above, their sutures slightly 

 depressed ; aperture oblique and ovate ; base attenuated. 



The length of the aperture scarcely exceeds half of the entire shell ; the whorls, which 

 are not numerous, are moderately wide, and somewhat flattened at their base ; the apex is 

 rather obtuse, and the general form is more cylindrical than is usual with shells of this 

 genus, the largest transverse diameter being only equal to the length of the last and penul- 

 timate whorl. We have only obtained two specimens which occurred in the soft shelly 

 Oolite underlying the planking, but, judging from casts, we should be inclined to believe 

 the upper portion of the formation likewise contains it. It has been named as a trifling 

 tribute of respect to H. E. Strickland, Esq., one of the few English geologists who, of late 

 years, have contributed to our knowledge of the Oolitic system. 



Locality. Minchinhampton. 



Natica Formosa. Plate VI, fig. 10. 



N. Testa ovato-elongatd, spird elatd, anfractibus (5) convexis, ultimo anfractu oblique 

 ventricoso ; aperturd magna ovatd ; basi rotundatd, labro sinistro excavato. 



Shell ovately-elongated, spire elevated, whorls (5) convex, the last whorl ventricose and 

 oblique ; the aperture large, ovate, the inner lip excavated, the base rounded. 



We were at first disposed to refer this species to Natica elegans, Sowerby, but an 

 examination of additional specimens has convinced us of its specific distinctness. As com- 

 pared with that species, the spire is always much larger, and less angulated, and the 

 aperture bears a much less proportion to the entire length, its longer diameter scarcely 

 amounting to three fifths of the entire length of the shell. It occurs both in the planking 

 and upper portion of the formation, but is somewhat rare. Length 26 lines, breadth 

 20 lines. The apex, when perfect, is more acute than our figure represents. 



Locality. Minchinhampton. 



Natica Tancredi. Plate VI, fig. 11. 



N. Testa ovatd, spird elatd, anfractibus (5) angustatis in medio subangulatis ; apice 

 obtuso ; anfractu ultimo subcylindrico, permagno ; aperturd obliqud angustatd; basi sub- 

 acuminatd. 



Shell ovate, spire elevated, whorls (5) narrow, somewhat angulated in their middle 

 portions ; the apex is obtuse, the last whorl is very large, and subcylindrical ; the aperture 

 oblique and narrow, the base somewhat pointed. 



