RAPHITOMA MITRULA. 269 



strong, prominent and flexuous costge, reaching the suture and the base of the 

 shell, and by excessively fine spiral lines ; suture slight ; mouth oval, not expanded, 

 angulate above ; canal distinct, short. 



Biinensions. — L. 7 — 10 mm. B. 3 — 4 mm. 



Distribution. — Recent ; Mediterranean. 



Fossil : Coralline Crag : Corner Pit. 



Upper Pliocene : Altavilla, Bologna, Caltabiano. Pleistocene : Messina, Livorno, 

 Valle Biaia (Seguenza). 



BemarJcs. — When studying the smaller forms of the present group one is often 

 in doubt how far the figures of the earlier writers can be depended on for the 

 identification of our Crag fossils. In the present case those of Scacchi and 

 Philippi differ so Avidely that it is hard to decide whether or not these authors 

 were referring to the same shell, that of the latter approaching the 71'. tui'gida of 

 Forbes, to which species, indeed, the B. nana of Scacchi has been generally 

 referred. I have, however, received some specimens from my friend, the Marchese 

 di Monterosato, for whose friendly and repeated assistance I can hardly feel 

 sufficiently grateful, which lead me to think the two species may be regarded as 

 distinct; some of these specimens he calls R. nana (PL XXX, fig. 32), informing 

 me they were taken from the collection of the Sicilian palgeontologist Brugnone ; 

 others, from the Pliocene deposit of Altavilla, he describes as R. nana, "j^roxima^' 

 (fig. 34). In the Montagu-Smith collection of the Sedgwick Museum at Cambridge 

 there is a fossil from the Coralline Crag of the Comer Pit (fig. 33) belonging to 

 the same group, and apparently identical with the latter ; allowing for the want of 

 conchological accuracy so frequently shown in the figures of the artists of the 

 early part of the nineteenth century, it does not seem unreasonable to suppose 

 that at least one of these represents the form originally represented by Scacchi. 

 If I am correct in referring the shell described above to the R. turglda of 

 Reeve (Forbes) this can hardly be regarded as the same. Philippi's drawing 

 of R. nana I am inclined to regard as B. turgida. As Seguenza's shells were not 

 figured it seems impossible to decide to which of these forms the fossils given by 

 him as R. nana belong. 



Raphitoma mitrula (S. V. Wood, ? Sowerby). Plate XXIX, figs. 23—25. 



1848. Clavahda mitrula, S. V. Wood, Mon. Crag Moll., pt. i, p. 59, pi. vii, fig. 7. 



1871. Pleurotoma costata, var., Jeffreys in Prestwicli, Quart. Journ. Geol. Soc, vol. xxvii, pp. 143, 



488. 



1881. Pleurotoma costata, Nyst, Couch. Terr. Tert. Belg., p. 52, pi. iii, fig. 17. 



Specific Characters. — Shell turreted, subfusiform ; whorls 6 — 7, convex ; orna- 

 mented by about ten strong, rounded, and prominent longitudinal ribs, which 

 hardly reach the base of the shell, and by irregular, inconspicuous spiral lines, not 



