19 



NOTE ON VIQUESNELIA OP DESHA YES FEOM THE MIOCENE 

 (SARMATIAN) OF TURKEY. 



By G. K. GuDE, F.Z.S. 

 Bead 10th November, 1911. 

 The genus Viquesnelia was established by Deshayes in 1857,' being 

 based on some simple testaceous rudiments found in great abundance 

 in nummulitic beds in lliimelia. These he considered to be the 

 internal shell of a limacoid Gastropod, which he named Viquesnelia 

 lenticular is. '^ A note was appended to this article by P. P'ischer, who 

 referred a mollusc from Mahe, Seychelles, and labelled Clypeicella 

 Dussumieri, Val., in the Paris Museum, to the same genus. Another 

 species discovered by Morelet & Drouet in the Azores was also placed 

 in this genus, and described by the former under the designation 

 Viquesnelia Atlantica? Neither of these, however, beai's any resemblance 

 to the type of Viquesnelia, as was pointed out subsequently by Fischer,* 

 who rejects the hypothesis that the Azorean mollusc is the living 

 representative of the genus, adding that no evidence exists that these 

 structures should be the internal shells of limacoids rather than 

 opercula. 



Morelet's species possesses a shell resembling Ancylus and is now 

 placed in the genus Plutonia, while Gray in 1855 * created the genus 

 Mariaella for the reception of the Seychelles species. 



D'Archiac^ had already previously restricted the genus to the type 

 and only species originally indicated by Deshayes. 



While recently working at some Turkish Tertiary MoUusca at the 

 British Museum I had occasion to examine the specimens forming part 

 of the set of fossils collected by A. F. Dabell, Esq., in the district 

 surrounding the Dardanelles, and presented by him to the National 

 Collection. 



The specimens of the so-called Viquesnelia lenticularis had been 

 obtained with other fossils from the Sarmatian Beds of the Tekfur 

 Dagh district, to the north of the Dardanelles. On examining these 

 I was at once struck with their resemblance to a molluscan 

 operculum. The outer or upper surface is slightly concave, has 

 a short spiral nucleus, situate considerably below the centre, 

 consisting of about IJ whorls. The spiral character then seems 

 to disappear and the lines of growth apparently become sub-ovate 

 or auriculate, the excentricity becoming emphasized by the closer 

 crowding together of the lines of growth at the lower and outer 

 (righty sides. A shallow groove proceeds upwards from the nucleus, 

 running more or less parallel with the right margin and traversing the 



^ Joum. de Conchyl., vol. v, p. 289. 



2 Tom. cit., p. 287, pi. vii, figs. 14-17. 



2 Hist. Nat. des A(;ores, 1860, p. 139, pi. i, fig. 1. 



■* Man. de Conchyl., 1883, p. 457. 



•' Cat. Pulm. Coll. Brit. Mus., pt. i, p. 62. 



® Viquesnel, Voyage dans la Turquic, vol. ii, p. 457, 1868. 



