BTTTTUM EOBUSTFM. 117 



1884. Bittium lacteum and vars., Bucquoy, Dautzenberg et Dollfus, Moll. mar. b'nuss., vol. i, p. 215, 



pi. xxvi, figs. 1 — 7. 

 1890. Bittium lacteum, Cams, Prod. Faun. Medit., vol. ii, p. 362. 

 1892. Bittium lacteum, Locard, Coq. mar. Cotes de France, p. 122. 

 1901-7. Bittium lacteum. Scalia, Atti Accad. G-ioen. Sci. Nat. Catania [4 a], vol. xiv, p. 13, 1901 ; 



vol. xx, p. 34, 1907. 

 1906. Bittium lacteum, Cossmann, Ess. Paleoconcb. compar., vol. vii, p. 137. 

 1908. Bittium lacteum, Kobelt, Icon, scbalentrag. europ. Meeresconcb., vol. iv, p. 103, pi. cxviii, 



figs. 23, 24. 

 1917. Inobittium lacteum, Monterosato, Moll. viv. e quat. Tripoli, p. 20; Boll. Soc. Zool. Ital. [3], 



vol. iv. 



Specific Characters. — Shell small, solid, turreted ; spire acuminate, suture 

 distinct ; whorls 7 or 8, flattened, gradually diminishing in size upwards towards a 

 blunt point; ornamented by three rows of strong, regularly spaced, but rather 

 inconspicuous tubercles; base rounded, with non-tuberculate ridges; mouth small, 

 ovate ; columella oblique, twisted near the base ; canal very short. 



Dimensions. — L. 7 mm. B. 2 - 5 mm. 



Distribution. — Recent: Scilly Isles (Marshall). Mediterranean, Adriatic, north 

 Atlantic as far south as Madeira. Tripoli. 



Fossil : Coralline Crag : Sutton ? Waltonian : Little Oakley. 



Post-Pliocene : Catania district. 



Remarks. — Except for a single specimen from the Coralline Crag of Sutton 

 reported by Wood with some doubt, the present Mediterranean and southern 

 species has not been recognized hitherto from the Crag ; I have found several 

 specimens, some of them imperfect, which appear to correspond with a recent shell 

 received from my friend M. Dautzenberg. Seguenza reports Cerithiolum lacteum 

 from the Upper Pleistocene of Sicily, identifying it with the C. elegans of 

 Blainville, but MM. Bucquoy and his colleagues, with Prof. Kobelt, in the works 

 referred to above, state that, in their opinion, it is the C. elegans of Weinkauff 

 rather than that of Blainville which truly represents the G. lacteum of Philippi. 

 The prolific pit at Little Oakley is the second Crag locality from which this 

 species has been recognized as a fossil. 



Dr. Scalia reports it from the sub-Etnaen deposits of Nizzeti, Catira, and 

 elsewhere. 



Bittium robustum, sp. nov. Plate XLI, figs. 9, 10. 



Specific Characters. — Shell turreted, strong and solid ; whorls 7 or 8, but 

 slightly convex ; spire regularly diminishing in size to a blunt point ; ornamented 

 by about 12 strong and oblique costas, equal to the spaces between them, and 

 by 3 or 4 well-marked spiral ridges which become coarsely tuberculate at the 



