Notes on Streptostele (Raffraya) horei E. A. Smith, 1890

The genus Streptostele H. Dohrn, 1866, inhabits continental Africa, Prince’s Island, Fernando Po, Mayotte Island and the Seychelles, and is subdivided ¹) into the subgenera Streptostele s.s., Varicostele Pilsbry, 1919, and Stereostele Pilsbry, 1919. Varicostele is only known from the Belgian Congo; Stereostele only from the Seychelles. These two subgenera contain no species with shells having a vertical rib-striation. The subgenus Streptostele s.s. is subdivided into four sections: Graptostele Pilsbry, 1919, the only section in which the shells have the embryonic whorls spirally engraved and the rest of the whorls smooth; Tomostele Ancey, 1885; Streptostele s.s., and Raffraya Bourguignat, 1883 (= Ischnostele C. Boettger, 1915).