428 PLIOCENE MOLLUSCA. 



] imposed for this group of shells a new genus. Our Crag shell is now generally 

 known as Ls&ocochlis granosa. 



MM. Dautzenberg and Fischer, recognising the difference as well as the 

 similarity between the recent and the fossil form, have adopted for the former 

 the name of L. granosa, var. Macanclrewse. Whether the separation should be 

 specific or varietal is a matter for zoologists; in any ease, Wood's specific name 

 of granosa holds good for the Crag shell. 



It may be pointed out, however, that the ascertained distribution of the two 

 does not overlap, either in time or space. The fossil form seems to have dis- 

 appeared from the Anglo-Belgian basin before the Icenian stage of the Pliocene 

 period, and it has not been reported from our Pleistocene deposits. The recent 

 shell has a distinctly northern range, crossing the Arctic circle and being unknown 

 in British seas. The figure of it given by Prof. Gr. 0. Sars ('Moll. Reg. arct. Norv.,' 

 pi. xiii, fig. 6) is quite characteristic. 



Genus TRICHOTROPIS, Broderip and Sowerby, 1829. 

 Trichotropis borealis, Broderip and Sowerby. Plate XLIV, figs. 36 — 38. 



1829. Trichotropis borealis, Broderip and Sowerby, Zool. Journ., vol. iv, p. 395. 



1841-70. Trichotropis borealis, Gould, Rep. Inv. Mass., ed. 1, p. 300, fig. 207, 1841 ; ed. 2. p. 390, 



fig. 651, 1870. 

 1842. Trichotropis atlantica, Moller, Iud. Moll. Groenl., p. 12. 

 1846. Trichotropis borealis, Loven, K. Svensk. Vet.-Akad. Forh., vol. iii, p. 87. 



1848. Trichotropis borealis, S. V. Wood, Mon. Crag Moll., pt. i, p. 67, pi. vii, fig. 17 ; pi. xix, fig. 11. 

 1853. Trichotropis borealis, Forbes and Hartley, Brit. Moll., vol. iii, p. 361, pi. ci, figs. 5, 6. 

 1867-71. Trichotropis borealis, Jeffreys, Brit. Couch., vol. iv, p. 245, 1867 ; vol. v, pi. lxxix, fig. 6, 



1869 ; in Prestwich, Quart. Journ. Geol. Soc, vol. xxvii, p. 145, 1871. 



1872. Trichotropis borealis, Dawson, Canadian Nat. (n. s.), vol. vi, p. 395. 



1873. Trichotropis borealis, Seguenza, Boll. E. Com. Geol. Ital., vol. iv, p. 350, fig. 233. 



1887. Trichotropis borealis, Mcirch and Poulsen, MS. list in Geol. Mus., Copenhagen, no. 59 (un- 

 published). 



1878. Trichotropis borealis, G. O. Sars, Moll. Reg. arct, Norv., ]>]>. 163, 358. 



1901. Trichotropis borealis, Priele og Greig, Norske Nordh. Exped. (Mollusca), pt. iii, p. 71. 



1901. Trichotropis borealis, Br0gger, Norges geol. Undersogel.se, no. 31, p. 653, pi. xvii, fig. 17. 



1913. Trichotropis borealis, Gignoux, Ann. Univ. Lyon, n.s. [1], vol. xxxvi, p. 548, pi. xiii. figs. In, 11. 



1915. Trichotropis borealis, Odhner, K. Svensk. Vet.-Akad. Handl., vol. liv, p. 173. 



Specific Characters. — Shell rather small, fairly solid, turreted, sub-fusiform, 

 pointed at each end ; whorls about 6, somewhat convex, the last much the largest, 

 longer than the spire; ornamented by strong projecting spiral ridges, four or five 

 on the body-whorl, including the base, two on others, the upper ridge angulating 

 the shell, also by very fine spiral lines in the interspaces and on the sloping shelf 



