112 MOLLUSC A OF THE GREAT OOLITE OF YORKSHIRE. 



Cerithium Beanii. Plate XV, fig. 5. 



C. Testa parvd, turritd, apice obtuso, anfractibus numerosis angustis, subplanis, 5 

 costatis ; costis tuberculosis, tuberculis circa 16 in ambitu ; costis incequalibus ; suturis 

 anfractibus profundi depressis. 



Shell small, turreted ; apex obtuse ; volutions numerous, narrow, rather flattened, 

 encircled with five rows of costae ; costae tuberculated, the tubercles being about 1 6 in a 

 volution ; ribs unequal ; the sutures of the whorls deeply depressed. 



The third and fifth row of costaa are less prominent than the others, the tubercles are 

 large and prominent, the length of a volution is less than half its transverse diameter, the 

 first two volutions are nearly smooth. Length 5 lines, transverse diameter 2 lines. 



Locality. Near Scarborough. 



Natica adducta. Plate XV, figs. 17, 17 a. 



Natica adducta, Phillips. 1835. Geol. of York., vol. i, t. 9. fig. 30. 



— — Williamson. Geol. Trans., 2d Series, vol. v, p. 241 . 



— — D'Orb. 1850. Prod. Paleont., p. 264. 



N. Testa globosd, spird elafd, anfractibus (4) converts, superne rotundatis, suturis 

 depressis, anfractu ultimo obliquo j aperturd ellipticd, umbilico obtecto. 



Shell globose, spire elevated and pointed, whorls (4) convex, with depressed sutures, 

 their upper portions rounded ; the last whorl oblique ; aperture large, elliptical ; inner lip 

 with a covered umbilicus. 



Natica grandis, Goldfuss, is our only Great Oolite species which approaches near to 

 this form ; but that shell, though greatly expanded, has not more volutions than the present 

 species, a fact which militates greatly against their identity. Length 9 lines, breadth 

 8 lines. 



Locality. Great Oolite near Scarborough. The original specimen figured by Phillips. 



Natica punctura. Plate XV, figs. 18, 18«. 



Littobjna punctura, Bean. 1839. Mag. Nat. Hist., p. 62, fig. 23. 

 — — Morris. 1843. Cat. Brit. Foss., p. 149. 



N. Testa ovato-ventricosd, spird elafd, acuta ; anfractibus (6) convexiusculis, suturis 

 profunda impressis ; anfractu ultimo magno, punctato et cingidato ; punctis minutis, in 



