562 PLIOCENE MOLLUSCA. 



flattened costse, occasionally varicose, Avith fine, distinct spiral lines ; spire elongate, 

 gradnally tapering ; snture well marked ; month oval, angulate above ; onter lip 

 gently rounded, inflected at the periphery ; inner lip straight below, forming an 

 angle at the base. 



Dimensions. — L. 10 mm. B. 2*5 mm. (when perfect). 



Dish-ibiitioit. — Not known living. 

 Fossil : St. Erth. 



Remarks. — This imperfect fossil has been identified by Mr. Bell as equivalent 

 to the one originally described by him as Ghemnifzia euterpe. Semper, an Oligocene 

 species. He now considers that to be a mistake, suggesting instead the name of 

 Prof. Kendall, one of the earliest investigators of the St. Erth deposits. 



Turbonilla post-acuticostata, Sacco. Plate XLIX, fig. 13. 



1873 — 84. Odostomia (Chemnitzia) aoitecostafa, Jeffreys, Rep. Brit. Assoc, Sections (Bradford), p. 112, 



1873 ; Proc. Zool. Soc. Loudon, p. 359, pi. xxvii, fig. 2, 1884. 

 1876. Turbonilla acuticostata, Segueuza, Boll. E. Com. Geo!. Ital., vol. vii, p. 92, no. 540, 1876. 

 1890. Turbonilla acuticostata, Carus, Prod. Faun. Medit., vol. ii, p. 284. 

 1892. Turbonilla post-acuticostata, Sacco, Moll. Tert. Terz. Piem., pi. xi, p. 76. 

 1905. Turbonilla acuticostata, Kobelt, Icon, sclialentrag. europ. Meeresconch., vol. iii, p. 151, pi. Ixxii, 



fig. 1. 



SjJecific Chnracfers. — Shell small, imperforate, obeliscal, solid, opaque; whorls 

 about 9, slightly convex, the last one-third the total length ; spire slender, elongate, 

 turreted, gradually tapering ; ornamented by strong, equal-sized, oblique costas, 

 equal to the intervening spaces, which do not extend below the periphery, where 

 they are intercepted by a fine spiral ridge ; apex intorted and with the base smooth ; 

 suture well defined ; mouth small, subquadrangular ; outer lip contracted above, 

 rounded below ; inner lip and columella thickened. 



Dimensions. — L. 7 mm. B. 2 mm. 



Distrihiifioji. — Becent : Bay of Biscay. Mediterranean — Palermo, Gabes, Rasel, 



Amoush. ■ 



Fossil : Coralline Crag : Sutton. 



Upper Pliocene : Altavilla. 



Bemarlcs. — There are two specimens in the British Museum from St. Erth (no. 

 10291) bearing the name of T. itcnticostata, but M. Dautzenberg thinks they have 

 been wrongly identified. The one now figured, which corresponds more nearly 

 with that originally described by Jeffreys, belongs to the York Museum and was 

 obtained from the Coralline Crag of Sutton; it seems a distinct form, which may 

 be separated from other species of the same group l)y the wide intervals between 

 its longitudinal costas. 



Prof. Sacco, however, objects to the use of the specific term acuticostata {op. 

 cif., p. 76) on the ground that the latter name had l)een used in 1870 by Speyer for 

 another shell, proposing to use j^ost-acnticostatii for it instead. 



