660 PLIOCENE MOLLUSCA. 



Var. patula, Thorpe. Plate LIU, fig. 16. 



1844. Littorina patula, Thorpe, Brit. Mar. Couch., Suppl., p. 259, pi. i, fig. 7. 



1853. Littorina patula, Forbes and Hanley, Brit. Moll., vol. iii, p. 36, pi. lxxxv, figs. 6 — 10. 



1859. Littorina patula, G. B. Sowerby, 111. Ind. Brit, Shells, pi. xii, fig. 18. 



1865. Littorina rudis, var. patula, Jeffreys, Brit. Couch., vol. iii, p. 365. 



1892. Littorina patula, Locard, Coq. mar. Cotes de France, p. 188. 



1901. Littorina rudis, var. patula, Couch. Soc. List, Journ. of Conch., vol. x, p. 17. 



1910. Littorina patula, 0yeu, K. Norske Vid. Selsk. Skrift., no. 9, p. 170. 



1912. Littorina saxatilis, var. patula, Dautzeuberg et Fischer, Camp. Scieut., Prince de Monaco, 



vol. xxxvii (Mollusques), p. 196, pi. ix, figs. 24, 25. 



Varietal Characters. — Shell small, subglobose, rather thin ; whorls 4 — 5, the 

 upper ones very small, the last large and expanded ; ornamented by spiral ridges 

 and by the lines of growth ; spire very short with an obtuse apex, placed 

 obliquely; mouth large, ovate, expanded; outer lip thin, forming a right angle 

 with the columella. 



Dimensions. — L. 12 — 15 mm. B. 10 — 13 mm. 



Distribution. — Recent: Shetland Islands — Unst, south coast of Ireland, Pen- 

 zance, north coast of France. 



Fossil: Icenian Crag : Bramerton (?). Topes-banks, Trondhjem. 



Remarks. — I have not a satisfactory specimen of this variety from the Crag, 

 but for reasons given in the last paragraph I figure a recent example from the 

 south of Ireland, belonging to the Holmes Collection in the Norwich Museum, 

 which agrees with some I have received from Dr. A. H. Cooke and from M. 

 Dautzenberg. The latter writer remarks that the figures given by Kobelt and by 

 Forbes and Hanley do not accurately represent the characteristic features of this 

 shell. It may be specially recognised by its short spire, placed rather obliquely, 

 and by its large and much-expanded mouth. 



Var. tenebrosa (Montagu). Plate LIU, figs. 17, 18. 



1803. Turbo tenebrosus, Montagu, Test. Brit., vol. ii, p. 303, pi. xx, fig. 4. 



1819. Turbo tenebrosus, Turton, Conch. Diet., p. 197, figs. 36, 37. 



1827 — 44. Turbo tenebrosus, Brown, 111. Conch, (it. Brit.,ed. 1, p. 16, 1827 ; Littorina tenebrosa, ed. 2, 



p. 128, pi. x, figs. 18, 19, 1844. 

 1841—70. Littorina tenebrosa, Gould, Rep. Inv. Mass., ed. 1, p. 259, fig. 10/;, 1841 ; ed. 2, p. 306, 



fig. 576, 1870. 

 1853. Littorina tenebrosa, Forbes and Hanley, Brit. Moll., vol. iii, p. 'SV, pi. lxxxiv, figs. 11, 12: 



pi. lxxxv, figs. 1 — 5. 

 1859. Littorina tenebrosa, G. B. Sowerby, 111. Ind. Brit. Shells, pi. xii, ftVs. 16, 17. 

 1864. Littorina tenebrosa, S. P. Woodward in White's Hist, of Norfolk, vol. iii, p. 118. 

 1865 — 69. Littorina rudis, var. tenebrosa, Jeffreys, Brit. Conch., vol. iii, p. 365, 1865; vol. v, pi. lxv, 



fig. 3 b, 1869. 

 1S72. Littorina tenebrosa, A. and R. Bell, Proc. Geol. Assoc, vol. ii, p, 213. 

 1892. Littorina tenebrosa, Locard, Coq. mar. Cotes de France, p. 188. 



