328 Transactions. — Geology. 



Clathurella rudis. 



Shell fusiform. Whorls 7, convex, with large, rounded, longitudinal 

 ribs, which are broader than the interstices ; there are 9 on a whorl, rising 

 abruptly at the posterior end and dying away anteriorly ; those of the body 

 whorl scarcely reaching half its length. Spiral ribs weak, about as broad 

 as the interstices, 9 on the spire whorls and 20-25 on the body whorl. Aper- 

 ture ovate, produced into a short anterior canal. 



Length, -43 inch ; breadth, -22 inch. Aperture, '22 inch. 



Locality. Waihao, in green-sand. 



Clathurella leptosoma. 



Shell small, elongato-fusiform, the spire produced and acute. Whorls 

 6-7, the first two smooth, the third spirally striated, the others longitu- 

 dinally ribbed and spirally striated ; all the whorls after the third slightly 

 angled. On the body whorl the longitudinal ribs are obsolete ; spire 

 whorls with two strong spiral stria? and other smaller ones ; body whorl 

 with the two strong spiral striae followed by about 20 small ones, regular 

 and equidistant. Aperture narrow, angled behind, produced anteriorly into 

 a short canal. 



Length, '25 inch ; breadth, # 08 inch. 



Locality. White Bock Kiver. 



Clathurella incisa. 

 Shell fusiform. Whorls 6-7, rounded, the first two embryonic, the 

 Others longitudinally plicated and strongly spirally ribbed. Longitudinal 

 plications 16 in a whorl ; spiral ribs 9 on the penultimate, and 13 on the 

 body whorl ; posterior spiral ribs about their own breadth apart, but the 

 four anterior ones on the body whorl further apart. Aperture ovate, pro- 

 duced into a short anterior canal. 



Length, '8 inch ; breadth, '42 inch. 



Locality. Te Aute, Hawke's Bay. Collected by Mr. A. Hamilton. 



Spiral ribs much stronger than in C. hamiltoni. 



Cassis senex. 

 Sti'uthiolaria senex, Hutton, Cat. Tert. Moll, of N.Z., p. 11. 

 Purpura excursa, Hutton, I.e., p. 6 (1873). 



An excellent specimen from Pareora shows that this species is a Cassis. 

 The inner lip has a large callus and is slightly rugose in front. The whole 

 shell is finely spirally striated, and there is sometimes a third row of 

 nodules on the body whorl. There are 12-17 nodules in a row on each 

 whorl. 



Cerithium bicorona. 



Shell subulate. Whorls flattened, spirally striated, the posterior half 

 With two rows of longitudinally elongated nodules, of which there are about 



