66 PLIOCENE MOLLUSCA. 



form N. limata. Bellardi, however, considered it to be specifically distinct, a view 

 shared by Seguenza, whose list of fossils from the Sicilian deposits, quoted above, 

 includes the names of both forms, as well as by MM, Dollfus and Dautzenberg, the 

 Marchese di Monterosato and others. 



Bellardi says the typical N. jjrj/smathlca of the Italian Pliocene is a longer shell 

 than N. Umata, having an acute spire and fewer longitudinal ribs, while the spiral 

 costse are stronger and less closely crowded together. 



The shell originally figured by Brocchi has, however, a shorter spire than that 

 of Bellardi, though otherwise it is of the same character. 



Homes figures two shells under the name B. 'prlsmaticum, one of them [op. clt., 

 pi. xii, fig. 13) corresponding fairly well with the Italian form, the other (fig. 14) 

 being smaller, with a shorter spire. 



Those given by Nyst under this name in 1843, however (Coq. Foss. Terr. Tert. 

 Belg., pi. xliii, fig. 12), and in 1881 (Conch. Terr. Tert. Belg., pi. ii, fig. 10), 

 have little resemblance to the typical N. prhmatlca ; indeed, he states as to his 

 figure of 1881 that it appears to be intermediate between the latter species and 

 N. serrata. He agrees, however, that JSf. limnta is a different shell. I have not 

 noticed the true Italian N. prismatica in the Belgian Crag. 



Wood figured a shell in 1848 under the present name (tab. iii, fig. 6), but in 

 his second Supplement (p. 3), finding his reference incorrect, described it as a new 

 species, N. microstoma. He included N. prismatica in his synoptical list, however, 

 stating that Mr. Canham had sent him a specimen from the Coralline Crag which 

 corresponded with Brocchi's figure. 



We find fossils at Oakley which may be referred, on the one hand to the 

 Pliocene iY. prismMica, corresponding to those from the Italian deposits, and on 

 the other to the Recent species, N. limata, our Crag specimens of the latter having 

 spiral striations as fine and delicate as in those now living in the bay of Naples. 



The Crag fossil here figured as N. prismatica has been identified by Prof. 

 Issel of Genoa with Brocchi's species ; it agrees with specimens I have collected 

 from several localities in Italy, one of them from Colle Valetti near Pisa being also 

 represented to show the identity of the two; the Crag jY. limata (PI. IV, fig. 1) 

 seems to me a different shell. 



Nassa clathrata (Born). Plate III, fig. 3. 



1780. Buccinum clathratum, Born, Mus. Caes. Vinci. Test., p. 261, pi. ix, figs. 17, 18. 



1814. Buccinum clathratum, Brocchi, Coucli. Foss. Subap., p. 338. 



1874-5. Nassa clathrata, Seguenza, Boll. E. Com. Geol., vol. v, p. 276, 1874 ; vol. vi, p. 278, 1875. 



1879. Nassa clathrata, Fontanues, Moll. Plioc. Vail. Elione, vol. i, p. 57, pi. v, fig. 2. 



1882. Nassa clathrata, var. A, Bellardi, Moll. Terr. Terz. Piem., pt. iii, p. 76, pi. v, fig. 5. 



1889. Nassa clathrata, Sacco, Cat. Pal. Bac. Terz. Piein., p. 106. 



1901. Nassa (Niotha) clatliraia, Cossmann, Ess. Pak'out. comp., pt. iv, p. 203, pi. ix, fig. 3. 



