442 PLIOCENE MOLLUSCA. 



It does not seem to me that the fossil described by Prof. Sacco from the Italian 

 Miocene and Pliocene, as T. tricarinata, var. communis, 1 is a characteristic speci- 

 men of the recent British shell; the T. t urris of Homes, identified by him with 

 the T. terebra of Zieten (non Gmelin), and with the T. com unmix of Bronn 

 (non Eisso) 2 is a different species. 



Turritella erosa, Couthouy. Plate XL1V, fig. 15. 



1838. Turritella erosa, Couthouy, Bost. Journ. Nat. Hist., vol. ii, p. 103, pi. iii, fig. 1. 



1841-70. Turritella erosa, Gould, Eep. Invert. Mass., ed. 1, p. 267, 1841 ; ed. 2, p. 317, fig. 585, 1870. 



1842. Turritella polar is, Moller, Iud. Moll. Grroenl., p. 10. 



1843. Turritella erosa, de Kay, Nat. Hist. New York, pt, v (Mollusca), p. 113, pi. vi, fig. 122. 

 1848-72. Turritella clathratula, S. V. Wood, Mou. Crag Moll., pt. i, p. 76, pi. ix, fig. 8, 1848 ; 



T. erosa, 1st Suppl., pt. i, p. 53, 1872. 

 1864. Turritella erosa, S. P. Woodward, Geol. Mag., vol. i, p. 53; in Gunn's Hist. Norfolk, ed. 3, 



p. 118. 

 1870. Turritella polaris, S. V. Wood, Jr., Quart. Journ. Geol. Soc, vol. xxvi, p. 93. 

 1872. Turritella erosa, Dawson, Canadian Nat. (n. s.), vol. vi, p. 389. 

 1877-84. Turritella erosa, Jeffreys, Ann. Mag. Nat. Hist. [4], vol. xix, p. 239, 1877; in Lamplugli, 



Quart, Journ. Geol. Soc, vol. xl, p. 319, 1884. 

 1880. Turritella erosa, Stewart, Proc. Belfast Nat. Field Club, Appendix, p. 174. 

 1898. Turritella erosa, Posselt, Medd. om Grtfnl., p. 218. 

 1915. Turritella erosa, Johnson, Bost. Soc. Nat. Hist., Occ papers, vol. vii ; Fauua of New England, 



pt. xiii, p. 122. 

 1917. Turritella polar is, A. Bell, Naturalist (Yorkshire), No. 722, p. 96. 



Specific Characters. — Shell solid, tnrreted, elongato-conical ; whorls about 10, 

 but slightly convex ; ornamented by from 3 to 5 rounded and closely-set spiral 

 ridges with numerous indistinct lines of growth ; spire regularly diminishing in 

 size upwards; suture distinct, but not deep; mouth small, subcircular; base 

 rounded. 



Dimensions. — L. 24 mm. B. 8 mm. 



Distribution . — Recent : (Circumpolar) Greenland, Labrador, Spitsbergen, 

 Behring Sea, Sitka, Gulf of St. Lawrence to Cape Cod, Banks of Newfoundland. 

 Japan. 



Fossil : Pleistocene : England — Bridlington, Dimlington. Scot- 

 land — Elie, King Edward. Ireland — Ballyrudder. Labrador, Riviere du Loup, 

 Montreal (?). 



Remarks. — This species, an arctic and North American form, has not been 

 recorded from the Crag, being known to English Palaeontologists from Bridlington 

 only. Sir J. W. Dawson gives it from the Pleistocene of Labrador and the St. 



1 Moll. Terr. Terz. Piem., pt, xix, p. 6, pi. i, fig. 15. 



* Foss. Moll. Tort. Wien, vol. i, p. 423, pi. xliii, figs. 15, 16. 



