58 



Subgcnus Fustiaria Stoliczka i86S. 



1868. Fusüa7-ia Stoliczka, Mem. Geol. Surv. India, Cretaceous Fauna of Southern India II, 



p. 439. Type D. poUtuin Linné. 

 1897. Fustiaria Pilsbry & Sharp, Man. of Conch., vol. XVII, p. 127. 



Shell regularly tapering, arcuate polished; either smooth or sculptured with regular encir- 

 cling grooves, dividing the surface of the tube into short oblique segments. Aperture circular. 

 Anal orifice round or ovate. Slit a very long, straight, linear cleft on the convex side. 



But few living species of Fustiaria are known; but there are numerous Tertiary forms 

 and perhaps some from the Cretaceous. (From Pilsbry). 



Key to species. 



I. Shell sculptured with many encircling grooves pohtuDi. 



II. Shell smooth. 



a. Colour milk-white stenoscliiznm. 



b. Reddish at the apex, anteriorly fading to white tenuijissum. 



*7i. Dentalitim poliitiin Linné. PI. I, fig. 20. 



1766. Dentalimii poliiuin Linné, Syst. Nat. (12), p. 1264. 



1825. Dentaliinii polituin Linné. Deshayes, Mém. Soc. Hist. Nat. Paris, II, p. 368, pi. 17, figs 8, 9. 

 1860. Deiitaliiiiii politum Linné. SowERBY, Thes. Conch. III, p. 99, pi. 225, fig. 46. 

 1864. Dentaliiini politum Linné. Desh., An. s. Vert. Bassin Paris, II, p. 215, pi. 2, figs 11 — 13. 

 1872. Dentaliuin politum Linné, Conch. Icon., pi. 6, fig. 38. 



1897. Dentaliuni politum Linné. PiLSBRY & Sharp, Man. of Conch., vol. XVII, p. 128, pi. 19, 

 figs 18 — 21. 

 Dentaliuin cburncuin Desh. non Linné. SOWB., Genera of shells fig. 6. 



Diagnosis. Shell slender, long, slowly tapering and regularly arcuate, polished. 

 Sculptured with many narrow encircling grooves, parallel with the peristome, and dividing the 

 surface into narrow, oblique segments. Aperture somewhat oblique, circular, the peristome acute. 

 Anal orifice rounded-ovate, somewhat channelled within at the position of the slit. Slit an 

 extremely narrow and long cleft on the convex side. 

 Length 58, diam. aperture 4,9 mill. 

 Length 39, diam. aperture 3,3 mill. 



Distr ibution. Paris Basin (Eocene); recent in Indian seas (Desh. and Sowb.); Indian 

 Ocean (Melvill & Standen). 



R e m a r k s. No specimens were obtained by the Siboga. Mr Pilsbry writes : Whether 

 the Eocene and living specimens referred to D. politum are identical is a question we have 

 no means of answering, as we have seen no recent specimens. It is admitted to the modern 

 fauna on the authority of Deshayes and Sowerby who state that they have e.xamined oriental 

 recent shells, although the former in his Paris Basin Invertebrates (p. 2 1 6) thinks that Linnaeus' 



