681 PLIOCENE MOLLUSCA. 



not unlike the present form; the other (fig. 6), with a longer spire, may be 

 equivalent to my N. exvarians (PI. LIV, figs. 15 and 16). M. Dautzenberg con- 

 siders that the one uoav generally recognised by French and Italian authorities as 

 X. helicina resembles more nearly that given by Prof. Sacco (op. cit.) than does 

 Brocchi's shell. My experience, however, leads me to think that it may be 

 unwise to depend too much on the absolute correctness of the drawings of 

 pre-photographic times. 



Natica (Lunatia) exilis, A. Bell, MS. Plate LVI, fig. 2D. 



Specific Characters. — Medium size, allied in form to X. occlusa, but having the 

 umbilicus partly closed ; whorls somewhat convex, overlapping, the last much 

 the largest ; umbilicus deep, partly open ; mouth rather long, expanded below, 

 angulated above; inner lip forming a thickened and somewhat flattened callus; 

 spire elevated; suture well marked. 



Dimensions. — L. 28 mm. B. 24 mm. 



Distribution. — Not reported living. 



Fossil : Tcenian Crag : Easton Bavent. 



lie mark*. — The specimen figured under this name was discovered by Mr. A. 

 Bell many years ago and sent by him to the York Museum, where until the present 

 it has been lost sight of. I adopt for it his undescribed name of X. e.r'dix. Inform 

 it has a superficial resemblance to X. <>crluxa but it belongs to a different group. 

 The umbilicus is deep and partly open. 



Natica (Lunatia) fusca, Blainville. Plate LIV, fig. 18. 



1825 — 30. Natica fusca, Blainville. Diet. Sci. Nat., vol. xxxiv, p. 249, 1825 ; Faun, franc, pi. xiv, 



fig. 3, 1830. 

 1844. Natica sordida, Philippi, Enum. Moll. Sic, vol. ii, p. 139, pi. xxiv, fig. 15. 

 1853. Natica sordida, Forbes and Hanley, Brit. Moll, vol. iii, p. 334, pi. c, figs. 5, 8. 

 1859. Natica sordida, G. B. Sowerby, 111. Ind. Brit. Shells, pi. xvi, fig. 18. 

 1867 — 85. Natica sordida, Jeffreys, Brit. Conch., vol. iv, p. 218, 1867 ; vol. v. p. 215. pi. lxxviii, fig. 3. 



1869 ; Proc Zool. Soc, p. 29, 1885. 

 1876. Natica fusca, Seguenza, Boll. R. Com. G-eol. Ital., vol. vii, p. 12, no. 492. 

 1878. Natica (Lunatia) fusca, Monterosato, Enum. e Sinon. Conch. Medit. (Giorn. Sci. Nat. ed 



Econ. Palermo, vol. xiii), p. 36. 

 1886. Natica sordida, Kendall and R. Bell, Quart. Journ. Geol. Soc, vol. xlii, p. 211. 

 1890. Natica ( Nat icina) fusca, Cams, Prod. Faun. Medit., vol. ii, p. 304. 

 1892. Natica fusca, Locard, Coq. mar. Cotes de France, p. 184. 



1897. Natica (Neve.rita) sordida, A. Bell, Trans. Roy. Geol. Soc. Cornwall, vol. xii, p. 145, pi. ii, fig. 2. 

 1901. Natica (Naticina) fusca, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. ii, p. 88, pi. liv, 



figs. 1 — 4. 

 1907. Natica (Nacca) fusca, Scalia, Atti Accad. Giorn. Sci. Nat. Catania [4], vol. xx, p. 32, no. 214. 

 1912. Natica (Naticina) fusca, Dautzenberg et Fischer, Camp., Scient. Prince de Monaco, vol. xxxvii 



(Mollusques), p. 238. 



