NASSA (HINIA) TRTVITTATA. 321 



1890. Nassa recticostata, Sacco, Boll. Soc. Geol. Ital., vol. ix, p. 210, no. 2580. 



1890. Nassa recticostata, C. Reid, Plioc. Dep. Britain, p. 248. 



1893-8. Nassa recticostata, A. Bell, Proc. Roy. Irish Acacl. [3], vol. ii, p. 626, 1893; Trans. Roy. 



Geol.. Soc. Cornwall, vol. xii, p. 140, pi. i, fig. 8, 1898. 

 1901. Nassa (Hinia) recticostata, Cossmann, Ess. Palcoconch. coinpar., vol. iv, p. 205. 



Specific Characters. — Shell small, oval, acutely conical ; whorls 6, but very 

 slightly convex, regularly diminishing upwards to a rather blunt, rounded apex ; 

 ornamented by more or less rectilinear costae, about 15 on the body-whorl, nearly 

 equal to the intervening spaces, which do not altogether reach the base of the shell, 

 and by very fine, closely-set spiral ridges crossing the ribs ; suture slight ; mouth 

 small and narrow, angulate above ; outer lip thickened, denticulate within, the 

 upper denticle being much the largest ; inner lip also denticulate, forming a thick 

 callus on the pillar ; canal turning to the left. 



Dimensions. — L. 8 mm. B. 3*5 mm. 



Distribution. — Recent : (?). 



Fossil : St. Erth. 



Upper Pliocene: Piedmont (very rare). 



Remarks — This shell, which is more or less abundant at St. Erth, was 

 identified by Wood with N. recticostata, a form originally described by Bellardi 

 as rare in the Astian deposits of Piedmont. M. Dollfus has expressed the opinion, 

 however, that it is identical with Biiccinum costellatum, Renier, first figured under 

 that name by Brocchi, but both Bellardi and Prof. Sacco doubt the identity of these 

 two species. Our fossil approaches very nearly some of the numerous varieties of 

 N. costellafa figured by Messrs. Bucquoy, Dautzenberg and Dollfus, a group which 

 includes A 7 ". Cuvieri, Payraudeau, Biiccinum variabile, Philippi, and other similar 

 forms. It resembles also some of the figures of A 7 , costellata given by Prof. 

 Kobelt; on the other hand it appears to me to differ materially from Brocchi's 

 original representation of B. costellatum. As the matter is evidently one of doubt, 

 I content myself with adopting provisionally Wood's reference of the St. Erth 

 fossil to N. recticostata, in which he has been followed by the brothers Bell, Prof. 

 Kendall and Mr. C. Reid ; this is the name, moreover, by which it has been known 

 for many years in all our collections. 



Nassa (Hinia) trivittata (Say). Plate XXXIV, figs. 1(3, 17. 



1821. Nassa trivittata, Say, Journ. Acad. Nat. Sci. Pliilad. [1], vol. ii, p. 231. 



1841-70. Nassa trivittata, Gould, Rep. Invert. Mass., ed. 1, p. 309, fig. 211, 1841 ; ed. 2, p. 364, 



fig. 632, 1870. 

 1858. Nassa (Tritia) trivittata, H. and A. Adams, Gen. Rec. Moll., vol. i, p. 122. 

 1885. Nassa trivittata, S. V. Wood in J. Starkie Gardner, Quart. Journ. Geol. Soc, vol. xli, p. 96. 

 1914. Nassa trivittata, F. W. Harnier, Plioc. Moll. Gt. Brit,, pt. i, p. 73. 



