TUEBOXILLA (PYRGOSTELIS) DENSECOSTATA. 507 



1870. Chemnitzia densecosiata, A. Bell. Journ. de Conch., vol. xviii, jx 350, uo. 330. 



1871—84. Odosfoma rufa, var., Jeffreys in Prestwich, Quart. Journ. Geol. Soc, vol. xwii, pp. 14.3, 



487, 1871 ; 0. rafa, var. denslcostafa, Proc. Zool. Soc. London, p. 356, 1884. 

 1872. Chemnitzia densecostafa, A. and R. Bell, Proc Geol. Assoc, vol. ii, p. 203. 

 1873—76. TurboniJla densecosiata, Se>>;uenza, Boll. R. Com. Geol Ital., vol. iv, p. 354, no. 310, 1873 ; 



vol. v, p. 282, uo. 112, 1874 : vol. vii, p. 92, uo. 539, 1876. 

 1878—84. Odostomia {THrboiiilla) riifa, var. exig/ia, Monterosato, Eniun. e Sinon. Conch. Medit. 



(Giorn. Soc. Scien. Nat. Palermo, vol. xiii), p. 93, 1878 ; Pyrg/dina {Pyryosfells) densecosfota, Nomen. 



Gen. e Spec. Conch. Medit., p. 90, 1884. 

 1883 — 98. Tiirbonilla densecostafa, Bucquoy, Dautzeuberg et Dollfus, Moll. mar. Rouss., vol. i, p. 183. 



pi. xxi, fig. 11, 1883 ; vol. ii, p. 812, 1898. 

 1890. Partheniiia (Pyrgostelis) densecostafa, Carus, Prod. Faun. Medit., vol. ii, p. 281. 

 1892. TurhoniUa densecostata, Looard, Coq. mar. Cotes de France, p. 140. 

 1905. Turbonilla (Pyrgostelis) densecostafa, Kobelt, Icon, schaleutrag. europ. Meeresconch., vol. iii, p. 



158, pi. Ixxiii, figs. 1, 28, 29. 

 1912. Turbonilla densecostafa, Tesch, Med. v. d. Rijks. v. Delfstoffen, No. 4, p. 74, no. 170. 

 1914. Turhondla densecostafa, CeruUi-Irelli, Palaeont. Ital., vol. x, p. 270, pi. xxiii, figs. 41 — 43. 



Specific Character's. — Shell small, slender, subcylindrical ; whorls 9 or 10, nearly 

 flat; spire elongate, turriculate, regularly diminishing in size upwards ; ornamented 

 by numerous closely-set and nearly straight costfe, wider than the interspaces, and 

 by excessively fine spiral strife ; suture well marked but not very deep, rather 

 oblique ; mouth ovate, angulated above. 



Dimensions. — L. 4 — 4'5 mm. B. 1 mm. 



Distribution. — Recent : Mediterranean, Adriatic. 



Fossil: St. Erth. Coralline Crag: Sutton. Amstelien: Holland. 



Lower Pliocene : Biot. 



Upper Pliocene : Monte Mario, Bologna. 



Pleistocene : Taranto, Livorno, Valle Biaia. 



Remarks . — There seems considerable difference of opinion as to which of the 

 many allied forms of this group should be included under Philippi's name, 

 Chemnitzia {TurhoniUa) densecostata. Prof. Sacco, for example, considers Wood's 

 C. densecostata to be different, proposing to call it T. {Pyrgostelis) rufa, var. 

 adensecostata^ while he thinks the T. densecostata oi Messrs. Bucquoy, Dautzenberg 

 and Dollfus belongs to a different sub-genus, StrloiurhoniUa.' As I have no sufficient 

 information at my disposal to enable me to express an independent opinion, I 

 content myself with describing and figuring specimens of the Crag fossil, using for 

 it provisionally Wood's specific name given above. Unfortunately but few of those 

 who have written on the subject have given figures by which we might have been 

 guided. The specimens here figured have been submitted to M. Dautzenberg for 

 verification. They belong to the St. Erth Collection in the British Museum, 

 where they bear the name here adopted. 



1 Moll. Terr. Terz. Piem., pt. xii, p. 4. ^ Qp. cit., pt. xi, p. 96. 



