582 PLIOCENE MOTJ.USCA. 



generally supposed. Beside tlie cases of its occurrence that have been somewhat 

 casually described, several others have lately turned up, forming an interesting 

 group of about 9 distinct English species. The specimen now figured belongs to 

 Mr. Headley, in whose collection it bears, in Jeffreys' writing, the name M. albula. 

 Some difference of opinion exists as to what should be regarded as the most 

 important characteristics by which the genus Menesthn may be distinguished. The 

 Marchese di Monterosato thinks it shoidd ))e used for a group of shells with the 

 apex of the Pyramidellidaa and the folded columella of Aetivoii. On the other hand, 

 Reeve and P. Fischer consider that its columella shoidd be entirely free from teeth 

 or folding. In Fischer's Manuel de Conchologie it is said to be a subgenus of 

 Eulimella, specially distinguished by its spiral or latticed sculpture. If all the 

 species described here as Mpne^llio are correctl}^ identified, such features are not 

 constant. 



Menestho suttonensis, S. V. AYood. Plate L, fig. 1. 



1882. Menestho suftonennis, S. V. Wood, Mon. Crag Moll., 3rd Suppl., p. 9, pi. i, fig. 11. 

 1890. Menestho suttonensis, C. Reid, Plioc. Dep. Brit., ]>. 247. 



Specific GJidvacfrrs. — Shell minute, ovato-turreted ; whorls 5, slightly convex, 

 the last about half the total length ; ornamented l)y 3 to 4 distinct spiral ridges ; 

 spire regularly decreasing in size upwards ; suture well marked ; mouth small, 

 ovate, angnlated above, rounded below. 



Diiaensions. — L. 2"5 mm. B. 1 mm. 



Distribution. — Recent: Not recorded living. 



Fossil: Coralline Crag : Sutton, 



Remarl-s. — This shell, known to Wood in 1882 by a unicjue and somewhat 

 imperfect specimen, was referred by him with some doubt to the genus Menestho. 

 It has not been met with since. My figure is photographed fi-om the one published 

 after his death in the last Supplement to the ' Monograph of the Crag Mollusca.' 



Menestho truncata, Etheridge and Bell. Plate L, fig. 3. 



1898. Menestho truncata, A. Bell, Trans. Roy. Geol. Soc. Cornwall, vol. xii, p. 154. 



Specific Characters. — Shell minute, ovate; whorls 5, slightly convex, the last 

 tumid, much the largest, three-fouiths the total length ; spire short, regularly 

 diminishing upwards to a rounded and truncated point; ornamented by well- 

 defined spiral ridges which extend to the base; suture slight; mouth ovate; 

 outer lip gently rounded, incurved at the periphery ; umbilical chink small, 

 inconspicuous. 



