440 PLTOCENE MOLLUSC. \. 



from the Upper Pliocene of Monte Mario has been figured by Sign. Cerulli-Irelli 

 (op. cit.), which lie also associates with T. tricar inata under the varietal name of 

 bicingulata. 



Wood's var. bicincta (op>. cit.) is the same as our present shell. Nyst's var. 

 bicincta l is, I consider, a different species. 



Turritella communis, Risso. Plate XLIII, fig. 15; Plate XLIV, figs. 1—6. 



1826. Turritella communis, Risso, Hist. nat. Europ. merid., vol. iv, p. 106, no. 246, fig. 37. 

 1842-72. Turritella terebra, S. V. Wood, Aim. Mag. Nat. Hist. [1], vol. ix, p. 534, 1842 ; T. communis, 



Moil. Crag Moll., pt. i, p. 74, pi. ix, fig. 9, 1848 ; T. terebra, 1st Suppl., pt. i, p. 53, 1872. 

 1853. Turritella communis, Forbes and Hanley, Brit. Moll., vol. iii, p. 172, pi. lxxxix, figs. 1 — 3. 

 1867-9. Turritella terebra, Jeffreys, Brit. Conch., vol. iv, p. 80, 1867; vol. v, p. 209, pi. lxx, fig. 6, 



1869. 

 1878. Turritella terebra, G. O. Sars, Moll. Reg. arct. Norv., pp. 185, 359. 

 1873-6. Turritella communis, Seguenza, Boll. R. Com. Ceol. Ital., vol. iv, p. 356, no. 334, 1873 ; 



vol. v, p. 282, no. 120, 1874; vol. vii, p. 100, no. 642, 1876. 

 1884. Turritella communis, and vars., Bucquov, Dautzenberg et Dollfus, Moll. mar. Rouss., vol. i, 



p. 224, pi. xxviii, figs. 6 — 11. 

 1890. Turritella communis, Carus, Prod. Faun. Medit., vol. ii, p. 354. 

 1892. Turritella communis, Locard, Coq. mar. Cotes de France, p. 125. 

 1901. Turritella terebra, Br0gger, Norges geol. Unders0gelse, no. 31, p. 660, pi. ix, fig. 9. 

 1903. Turritella terebra, Lainplugh, Mem. Ceol. Surv. (Isle of Man), p. 473. 

 1912. Turritella terebra, Tesch, Med. v. d. Rijks. v. Delfstoffen, no. iv, p. 72, no. 164. 



1912. Turritella tricarinata, var. communis, Cerulli-Irelli, Palaeont. Ital., vol. xviii, p. 159, pi. xxiv, 

 figs. 30—33. 



1913. Turritella communis, Grignoux, Ann. Univ. Lyon, n. s. [1], vol. xxxvi, p. 552. 



Specific Characters. — Shell solid, slender, elongate, with a narrow and angu- 

 lated base ; whorls more or less convex, compressed on each side of the suture, 

 regularly diminishing in size to an acute point; generally ornamented by fine, 

 rather inconspicuous spiral ridges, three on the upper whorls, more on the lower, 

 some of them still finer, with closely-set strise in the lines of growth ; suture fairly 

 deep ; mouth rounded ; outer lip incurved above, angulated at the base ; inner lip 

 reflected on the pillar. 



Dimensions. — L. 35 — 50 mm. B. 10 — 15 mm. 



Distribution.— Recent : generally diffused in British seas and on the Atlantic 

 coasts from Morocco to the Lofoten Islands. Iceland. Mediterranean (passim), 

 Adriatic, JEge&n, Asia Minor. 



Fossil: Newbournian Crag : Sutton? Butleyan : Butley ; prob- 

 ably elsewhere in the upper zones of the Red Crag. Icenian : Norwich, Chilles- 

 ford and Weybourne horizons, common at most localities. Isle of Man. Wexford. 



1 Conch. Terr. Tert Belg., p. 83, pi. vi, fig. 12^, 1881. 



