NAISSA KMILIANA. 67 



Specific Gharacfers. — Shell strong, ovate, conical, wborls distinctly convex, the 

 last ventricose, much the largest, more than half the total length, excavated below ; 

 spire comparatively short, ending in a rather blunt point ; suture deep and 

 channelled ; ornamented by strong longitudinal costee, 14 to 20 on the body-whorl, 

 and by regular equidistant spiral ribs ; mouth oval, angulate above ; outer lip 

 rounded, plicated within ; columella excavated ; canal wide, very short. 



Dimensions. — L. 30 mm. B. IS mm. 



Distribiifiou. — Not known living. 



Foi<sil : Waltonian Crag : Little Oakley. 



Pliocene : Piedmont and Liguria. Upper Pliocene and Pleistocene : Sicily. 



Remarks. — I have one or two specimens from Oakley belonging to the N. 

 prismafica group, but differing distinctly from that species in their more tumid 

 form and their coarser sculpture. Submitting them to Prof. Issel, he had no 

 hesitation in recognising them as a variety of N. clathrnia. They approach most 

 nearly to var. A of Bellardi's Monograph. It is interesting to find in the Oakley 

 Crag so many forms of Nassa, characteristic of the Mediterranean Pliocene, which 

 now have wholly disappeared from more northern seas. 



M. Cossmann has recently referred this species, together with N. serrata, 

 N. Cantrainii and some others, to the sub-genus Niotha of H. and A. Adams. 



Nassa emiliana (Mayer), var. A, Bellardi. Plate IV, figs. 5, 6. 



1843. Buccinum lyrismaticum, Nyst, Coq. Foss. Terr. Tert. Belg., p. 576, pi. xliii, fig. 12. 



1872. Buccinum emilianum, Mayer, Journ. de Conch., vol. xx, p. 236, pi. xiv, fig. 9. 



1873. Nassa Michelottiana, Cocconi, Mem. Accad. Sci. Bologna, vol. iii, p. 48-5, pi. i, figs. 21, 22. 

 1882. Nassa emiliana, var. A, Bellardi, Moll. Terr. Terz. Piem., pt. iii, j). 77, pi. v, fig. 6. 

 1898. Nassa emiliana, Etheridge and A. Bell, Trans. Roy. Geol. Soc. Cornwall, vol. xii, p. 141. 

 1912. Nassa emiliana, Tesch, Med. v. d. Rijks. v. Delfstoffen, pt. iv, p. 80. 



Specific Characters. — Shell smaller and less elongate than any of the group 

 before described, ovate, turreted ; spire short; whorls convex, flattened above, the 

 last more than half the total length ; ornamented by 15 or 10 longitudinal ribs, 

 prominent and obtuse, separated by furrows, equal in width to the ribs and crossed 

 by strong spiral costas, about 16 on the body-whorl, which become slightly nodular 

 at the point of intersection ; apex acute ; mouth oval, angulated above ; outer lip 

 grooved within, but little thickened externally ; inner lip folded upon the pillar ; 

 canal wide and open, turning to the left, ending in a deep notch. 



Dimensions. — L. 15 mm. B. 9 mm. 



Distribution. — Not known living. 



Fossil : Coralline Crag : Boyton. Waltonian : Little Oakley ; 

 probably elsewhere in the Red Crag. St. Erth. Scaldisien : Belgium. Miocene 

 and Pliocene : Italy. 



