NASSA PUSILLINA. 81 



little shell to my old friend in acknowledgment of the assistance Jie has so willingly 

 give n me for many years. 



N. JJollfiisli seems specially distinguished by its form, the coarseness of its 

 sculpture, both longitudinal and transverse, and by the strongly marked fluting on 

 the inner lip. 



Var. convexa, nov. Plate V, fig. 10. 



Bemaiis. — This distinct form, also from Oakley, seems to belong to the present 

 group, having the same coarse ridges on the inner lip. It differs from the type, 

 however, in the greater convexity of its whorls, and in its longitudinal costfB, which 

 are fewer and more prominent. 



Nassa pusillina, S. V. Wood. Plate V, figs. 27, 28. 



1864. Nassa s^., S. P. Woodward, in White's History of Norfolk, 3rd ed., p. 117. 

 1870. Nassa push, S. V. Wood, jun., and F. W. Hariner, Eep. Brit. Assoc. (Liverpool), Trans. Sect., 

 p. 90. 



1870. Nassa variabilis, A. Bell, Auu. Mag. Nat. Hist. [4], vol. vi, p. 29. 



1871. Nassa Guvieri, Jeffreys, in Prestwicli, Quart. Journ. Geol. Soc, vol. xxvii, p. 489. 



1872-4. Nassa pusilina, S. V. Wood, Mon. Crag Moll., 1st Suppl., p. 14, tab. ii, fig. 7, 1872; and 

 var. variabilis, p. 176, Addendum plate, fig. 24, 1874. 



Specif c Characters. — Shell small, slender, elongate ; whorls 6, but slightly 

 convex, regularly tapering to a fine rounded jDoint, the two first smooth, the others 

 ornamented with about 10 flexuous longitudinal costge, narrower than the spaces 

 between them, with very fine, delicately chiselled spiral striae wdiich cross the ribs 

 but hardly cause tuberculation at the point of contact ; last whorl not pinched up 

 above the canal, as in N. incrassata ; suture slight; mouth ovate, acutely angulate 

 above, short, from one-third to one-fourth the total length of the shell ; canal very 

 short, open ; inner lip reflectea on the pillar. 



Dimensions. — L. 8 mm. B. 3 mm. 



JJistribiUioit. — Not known living. 



Fossil : Newbournian Crag: Ramsholt (Ogden). Butleyan : Butley, 

 Bawdsey. Icenian : Beccles, Bramerton (not rare). Middle Glacial Sands : 

 Billockby. 



Remarks. — There is some confusion as to the correct nomenclature of this 

 charming little shell, which has been known to Norfolk collectors from the time 

 of S. P. Woodward onwards. In the list of fossils from the Norwich Crag 

 published by the latter (oj). cit.), it is given, on the authority of the late R. Wigham, 

 as " Nassa sp., slender, pointed, examples in all collections." It was at first 

 called iV. pusio by Wood the younger and myself, but as this name had been 



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