TRIVIA EUROP^A. 49 



THE MARINE MOLLUSCA OE THE CRAG. 



GASTEROPODA. 



Genus TRIVIA, Gray, 1832. 

 Trivia europaea (Montagu). 



1758. Cyprma pediculus, var. europasa, Linm', Syst. Nat., ed. x, p. 724, uo. 522. 



1808. Cyprxa eurojjxa, Moutagu, Test. Brit., Suppl., p. 88. 



1848. Cyprsea europxa, S. V. Wood, Mon. Crag Moll., pt. i, p. 17, tab. ii, fig. 6. 



1853. Cyprxa europxa, Forbes and Hanley, Brit. Moll., vol. iii, p. 495, pi. cxiv, figs. 6-9. 



1867. Cyprsea europxa, Jeffreys, Brit. Conch., vol. iv, p. 403, pi. xcii, fig. 2. 



1877. Trivia europxa, var. coccinelloides, Sacco, Moll. Terr. Terz. Pieru., pt. xv, p. 46, pi. iii, fig. 27. 



1883. Cypreea {Trivia) europeea, Bucquoy, Dautzenberg et DoUt'us, Moll. mar. Rouss., vol. i, p. 127, 

 pi. xvi, fig. 18. 



Distribution. — Recent : British Seas, Scandinavia, West] European, Mediter- 

 ranean. 



Fossil : Miocene, Pliocene, Pleistocene. 



Remarks. — Specimens of this British species occur in all parts of the English 

 Crag, being especially abundant in the Waltonian zone at Little Oakley, most of 

 them corresponding in size with those usually found in the North Sea ; they 

 generally measure from 9 to 12 mm. in length, but smaller and larger ones are met 

 "with also at the latter place and elsewhere. S. V. Wood remarks that the Crag 

 shells vary in size from ^ in. to f in. (3 to 16 mm.), all of them being full grown ; 

 he says he had never obtained an immature specimen. 



The Marchese di Monterosato distinguishes the smallest as var. minor, while 

 M. Bucquoy and his collaborateurs adopt Philippi's name of major for those of 

 14 mm. 



Var. sphsericulata, Lamarck. Plate II, figs. 15, 16. 



1810. Cyprsea sphxriculata, Lamarck. Ann. Mus. Hist. Nat., vol. xvi, p. 107. 



1873-5. Trivia sphsericulata, Seguenza, Boll. E. Com. GeoL, vol. iv, p. 294, 1873; vol. vi, p. 153, 1875. 

 1886. Trivia europsea, var. sphiericulata, Dollfus et Dautzenberg, Et. prel. Coq. foss. Tour., p. 13. 

 1894. Trivia sphserimdata, Sacco, Moll. Terr. Terz. Piem., pt. xv, p. 47, pi. iii, fig. 29. 



Dimensions. — L. 16 — 20 mm. B. 12 — 14 mm. 



Distribution. — Not known living. 



