446 PLIOCENE MOLLUSCA. 



Dimension*. — L. 20—25 mm. B. 6—8 mm. 



Distribution. — Recent: Mediterranean— Nice, coasts of Algeria, Tunis, and 

 Syria. 



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



Remarks. — The recent shell here figured is one I received from the Marchese 

 de Monterosato as a typical specimen of his T. decipiens, a species now occurring 

 rarely at certain localities in the Mediterranean. It differs from T. subangulata 

 and its variety acutangala (mediocarinata) in its much smaller and more slender 

 form, and in its concave and sharply angulated base. Dr. Cams, who adopts the 

 name T. decipiens for the recent shell, considers it equivalent to Brocchi's T. acut- 

 angula, but the other authorities quoted regard it as specifically distinct, Dr. 

 Gignoux remarking that the one is an Italian Pliocene and extinct shell, the other 

 a recent and much smaller form. 



The Coralline Crag specimen figured by Wood as T. incrassata, var. acutangula, 

 and another I obtained at Oakley, one being 10 mm. and the other 15 mm. in 

 length, may be referred, I think, to the small recent species mentioned, with 

 which they agree more closely than with the much larger and extinct fossil 

 T. acutangula. The twisted apex of the recent specimen corresponds with that 

 shown in Wood's figure. 



In some respects our shell approaches the Turbo spiratus of Brocchi [op. cit., 

 pi. vi, fig. 19), from which it may possibly have descended. 



Sub-genus HAUSTATOR, Montfort, 1810. 



Turritella (Haustator) incrassata (J. Sowerby). Plate XLII, figs. 1—3; 5 — 7; 



Plate XLIIT, fig. 16. 



1814. Turritella incrassata, J. Sowerby, Min. Conch., vol. i, p. iii, pi. li, fig. 6. 



1842-48. Turritella incrassata, S. V. Wood, Ann. Mag. Nat. Hist. [1], vol. ix. p. 534, 1842; Mon. 



Crag Moll., pt. i, p. 75, pi. ix, figs. 7 a, 7 c, 1848. 

 1843-81. Turritella trijplicata, Nyst, Coq. foss. Terr. tert. Belg., p. 400, pi. xxxvii, figs. 7, 8, 1843 ; 



T. incrassata, Conch. Terr. Tert. Belg., p. 82, pi. vi, fig. 12 c, 1881. 



1871. Turritella triplicate/,, Jeffreys in Prestwich, Quart. Journ. Geol. Soc, vol. xxvii, pp. 146, 492. 



1872. Turritella incrassata, A. and E. Bell, Proc. Geol. Assoc, vol. ii, pp. 204, 210, 214, 216. 

 1885. Turritella incrassata, Lorie, Arch. Mus. Teyler [2], vol. ii, pp. 186, 230 (pt.). 



1896. Turritella incrassata, Bernays, Bull. Soc. Beige Geol., vol. x (Memoires), p. 131. 



1898-1900. Turritella incrassata, F. W. Harmer, Quart. Journ. Geol. Soc, vol. liv, pp. 317, 319, 1898 ; 



vol. lvi, pp. 712, 723, 1900. 

 1912. Turritella (Haustator) incrassata, Cossmann, Ess. Paleoconch. compar., vol. ix, p. 118. 

 1912. Turritella incrassata, Tesch, Med. v. d. Rijks. v. Delfstoffen, no. iv, p. 72, no. 163. 

 1915. Turritella incrassata, A. Bell, Geol. Mag. [6], vol. ii, p. 167. 



SjJeciftc Characters. — Shell large, fairly solid, turreted ; whorls generally 

 flattened, or but slightly convex ; spire elongate, conical, regularly tapering to an 



