632 PLIOCENE MOLLUSCA. 



1803. Turbo interruptus, Donovan, Nat. Hist. Brit. Shells, vol. v, pi. clxxviii, fig. 2. 



1853. Rissoa parva, var. mterrupta, Forbes and Hanley, Brit. Moll., vol. iii, p. 100. 



1859. Eissoa parva, var. interrupta, Gr. B. Sowerby, 111. Ind. Brit. Shells, pi. xiii, fig. 17. 



1863—84. Eissoa parva, var. interrupta, Jeffreys, Eep. Brit. Assoc. (Newcastle-ou-Tyne), p. 78, 1863 ; 



Brit. Conch., vol. iv, p. 24, 1867; vol. v, p. 207, pi. Ixvii, fig. 4, 1869; Quart. Jonrn. Geol. Soc, 



vol. xl, p. 319, 1884. 

 1871. Eissoa parva, var. interrupta, F. W. Harmer, Trans. Norf. Norw. Nat. Soc, vol. i, pt. 3, p. 46. 

 1 878. Eissoa parva, Monterosato, Enum. e Sin. Conch. Medit. (Giorn. Soc. Sci. Nat. Palermo, vol. xiii), 



p. 83. 

 1878. Eissoa interrvpta, O. 0. Sars, Moll. Reg. Arct. Norv., pp. 180, 359, pi. x, fig. 9. 

 1884 — 98. Eissoa {Tnrhella) parva, var. interrupta, Bucquoy, Dautzenberg et Dollfus, Moll. mar. 



Eouss., vol. i, p. 274, pi. xxxii, figs. 13-15, 1884; vol. ii, p. 787, 1898. 

 1890. Bissoa interrupta, Cams, Prod. Faun. Medit., vol. ii, p. 325. 

 1890 — 92. Eissoa parva, var. interrupta, A. Bell, Proc. Roy. Phys. Soc, Edin., vol. x, p. 292, 1890; 



Rep. Torks. Phil. Soc, p. 63, 1892. 

 1892. Eissoa interrupta, Locard, Coq. mar. Cotes de France, p. 173. 



1901. Eissoa interrupta, Br0gger, Norges geol. Under s,(5^gelse. No. 31, p. 657, pi. xvii, fig. 12. 

 1901. Eissoa 2)arva, var. interrupta. Conch. Soc. List, Journ. of Conch., vol. x, p. 17, no. 9. 

 1910. Eissoa interrupta, 0yen, Kongl. Norske Vid. Selsk. Skrift., pp. 34 et seq. 



1912. Eissoa (Turhella) parva, var. interrupta, Dautzenberg et Fischer, Camp, scient. Prince de 

 Monaco, vol. xxxvii (Mollusques), p. 208. 



1913. Eissoa (Turbella) parva, var. interrupta, Dautzenberg et Durouchoux, Feuille des Jeunes 

 Natur., vol. xliv, p. 29, pi. ii, fig. 4. 



Varietal Characters. — Shell minute, more slender and elongate than the type 

 form ; whorls less convex and without or with a few longitudinal ribs ; suture 

 slight. 



Dimensions. — L. 3 mm. B. 1*5 mm. 



Distribution. — Recent : British seas, coast of Western Europe as far north as 

 Finmark and the Lofoten Islands. St. Malo, Mediterranean — Rousillon, 

 Cartagena. 



Fossil : Waltonian Crag : Little Oakley. 



Pleistocene : Bridlington, Selsey, Largo Bay, Caithness and elsewhere in 

 Scotland (common). Estuarine clays, Belfast. Holocene : Portrush, Larne. 



Pleistocene : Uddevalla, Isocardia- and Tapes-hanks of Christiania (Br^gger), 

 Trondhjem (0yen). 



Remarks. — Formerly regarded as specifically distinct, tlie present form is now 

 more often considered as a variety of B. parva. It generally differs from the 

 latter in the absence of the strong longitudinal costge generally characteristic of that 

 species. I have found it as recent on the Norfolk coast, and Dr. Grwyn Jeffreys 

 informed me it had been dredged from the Lynn deeps. It has been recorded also 

 from one or two points in the Mediterranean, Imt its range seems to be mainly 

 northern.^ Dr. 0yen has compared my Oakley fossil with specimens in the 

 Museum at Christiania and reports that they are identical. 



1 Jeffreys, op. cit., vol. iv, p. 25. 



