6'S6 PLIOCENE MOLLUSCA. 



shell, but are cut off abruptly by a fine marginal ridge, tlie inside of the outer lip 

 is distinctly grooved, the suture is well-marked but not deep, and the whorls but 

 slightly convex. The specimen here figured belongs to the British Museum. 

 Mr. Bell reports it also from that of the Royal Greological Society of Cornwall at 

 Penzance. 



Suh-geuus PERSEPHONA, Leach, MS., 1852. 

 Rissoa (Persephona) violacea (Desmarest). Plate LI, fig. 8. 



1814. Rissoa (Persephona) violacea, Desmarest, Bull. Soc. pliiloni. Paris, p. 8, pi. i, fig. 1. 

 1826. Rissoa violacea, Eisso, Hist, iiatur. Europ. mc'rid., vol. iv, p. 120, pi. v, fig. 58. 

 1836—44. Rissoa OToZa.(!ea, Philippi, Enuiii. Moll. Sic, vol. i, p. 1.50, 1836; vol. ii, p. 124, 1844. 

 1844. Rissoa rufilahrum, Alder, Ami. Mag. Nat. Hist. [1], vol. xiii, p. 325, pi. viii, figs. 10, 11. 

 1853. Rissoa rufilahrum, Forbes and Hanley, Brit. Moll., vol. iii, p. 106, pi. Ixxvii, figs. 8, 9. 

 1867-69. Rissoa violacea, Jeffreys, Brit. Couch., vol. iv, p. 33, 1867 ; vol. v, p. 208, pl. Ixvii, fig. 9, 



1869. 

 1868-73. Rissoa violacea, Weiukauff, Concli. Mittelm., vol. ii, p. 300, 1868 ; Catal., p. 19, no. 296, 



1873. 

 1874. Rissoa violacea, Segueuza, Boll. K. Com. Greol. Ital., vol. v, p. 4, no. 370. 

 1878. Rissoa violacea, G. 0. Sars., Moll. Eeg. Arct. Norv., pp. 180, 359, pl. x, fig. 8, 

 1878 — 84. PersejJiona violacea, Monterosato, Enum. e Siuou. Conch. Medit., p. 24, 1878 ; Nom. 



Gen. e Spec. Conch. Medit., p. 58, 1884. 

 1884. Rissoa {Persephona) violacea, Bucquoy, Dautzenberg et Dollfus, Moll. mar. Rouss., vol. i, 



p. 280, pl. xxxiv, figs. 18—22. 

 1890. Rissoa (Persephona) violacea, Cams, Prod. Faun. Medit., vol. ii, p. 321. 

 1892. Rissoia violacea, Locard, Coq. mar. Cotes de France, p. 170, fig. 146. 

 1901. Rissoa violacea, Br^gger, Norges geol. Unders0gelse, No. 31, pp. 513, 660. 

 1913. Rissoa (Persephona) ?)7ac?«YT, Dautzenberg et Durouchoux, Peuille des Jeunes Natur., vol. xliv, 



p. 29, pl. ii, fig. 6. 



Specific Characters. — Shell small, solid, ovato-conical ; Avhorls 7, slightly convex, 

 the upper ones smooth, the penultimate ornamented on both sides and on the under 

 side of the last whorl by strong and prominent longitudinal ribs; the upper part 

 of the last and the base by many minute and regular punctures, together with 

 fine spiral ridges ; mouth ovate, angulate above, the outer lip thickened outside ; 

 suture slight ; spire short, regularly tapering to a fine point. 



Dimensions. — L. 6 mm. B. 3 mm. 



Distribution. — Recent : British Seas, south and west, from Guernsey to Shetland. 



Connemara, Belfast. Lough Strangford. From the Lofoten Isles, Finmark, 



Cattegat, to the coasts of France and as far south as Vigo. Mediterranean, Adriatic. 



Fossil : Pleistocene : Belfast. Tapes-hanks : Christiania fiord. 



Messina, Nice, Livorno, Rhodes. 



Remarks. — This species seems to be known as a British fossil fi'om the Belfast 



