584 PLIOCENE MOLLUSC A. 



cafuht, but if we consider it identical with Wood's 0. derivata, that name (1879), 

 although, as I think, unsuitable, has the priority. The M. truucatuhi of Odhner 

 and the 0. derivata of Wood correspond closely both in form and sculpture, though 

 in our specimen the spiral marking seems somewhat finer. 



Menestho Stefanisi (Jeffreys). Plate 1j, fig. 5. 



1842—72. Bissoa costulata (pt ), S. V. Wood (uou Alder), Auu. Mag. Nat. Hist. [1], vol. ix, p. 533, 

 1842 ; Moil. Crag Moll., pt. i, p. 10f5, pi. xi, fig. 12 a, 1848 ; B. Stefanisi, 1st. Siippl., pt. i, p. 73, 1872. 



1869—84. Rissoa Stefanisi (pt.), Jeffreys, Brit. Condi., vol. v, p. 208, 1869 ; in Prestwicli (pt.). 

 Quart. Joiu-n. Geol. Soc, vol. xxvii, pp. 145, 491, 1871 ; Proc. Zool. Soc, p. 123, 1884. 



1870. Bissoa Slefa)iisi, A. Bell, Journ. de Conch., vol. xviii, p. 355. 



1872. Bissoa Stefanisi, A. and E. Bell, Proc. Geol. Assoc , vol. ii, pp. 204, 210. 



1890. Bissoa Stefanisi, C. Keid, Plioc. Dep. Brit., p. 255. 



Specijic Ghanicters. — ^Shell small, elongato-turreted ; wdiorls 0, compressed, 

 squarely angulate below the suture; ornamented by numerous longitudinal costae, 

 slightly nodulous on the keel, witli narrow interspaces, and l)y delicate spiral 

 lines ; suture deep, slightly channelled ; S})ire gradually decreasing upwards 

 towards a small and rounded point ; mouth ovate, angulate above, rounded below, 

 striated within ; umbilicus small. 



Di'iiienslons. — L. G mm. B. 2 mm. 



Distribution. — Recent: Mediterranean (rare), l^eneriffe. 



jPb^'siL- Coralline ('rag : Gedgi-ave, Sutton. Waltonian : Walton- 

 on-Naze, Little Oakley. Newbournian : Waldringfield. Biot. Sicily. 



ReAiiarlis. — Two shells, differing materially in form and sculpture, were described 

 in 1848 by Wood as Bissoa costulata. At present they are both known generically 

 as Menestho, but specifically are regarded as distinct, the larger of the two, the 

 one here figured as M. Stefanisi (PI. L, fig. 5), retaining that name, which was 

 suggested by Jeffreys as the result of an examination of General Stefani's Collection 

 at Naples^ where he found a si)ecimen of the shell in ([uestion said to have been 

 obtained in Sicily, though the precise locality from which it came is not stated. 

 The supposed occurrence of this species at Waldringfield is somewhat doubtful. 



Menestho JefFreysii, A. Bell. Plate L, fig. G. 



1842—74. Bissoa costulata (pt.), S. V. Wood (not Alder), Auu. Mag. Nat. Hist. [1], vol. ix, 

 p. 533, 1842; Mon. Crag Moll., pt. i, p. 106, pi. xi, fig. 12 b, 1848; Menestho Jeffreysii, 1st 

 Suppl,, pt. ii, pp. 185, 208, 1874. 



1871—1911. Menestho Jeffreysii, A. Bell, Aun. Mag. Nat. Hist. [4], vol. vii, p. 360, 1871; Journ. 

 Ipsw. Field Club, vol. iii, p. 15, 1911. 



1 Brit. Conch., vol. v, p. 208. 



