New Orthalicidae (Mollusca, Gastropoda) from Venezuelan Guayana: unravelling secrets from the Lost World Author Breure, Abraham S. H. text Zootaxa 2009 2065 25 50 journal article 10.5281/zenodo.186920 695e995e-3a9a-41b8-bafa-ed8366b37ef4 1175-5326 186920 Subgenus Plekocheilus (Plekocheilus) Guilding, 1828 Plekocheilus (Plekocheilus) fulminans linterae ( Sowerby, 1890 ) ( Figs 4 A─D, 9A) Bulimus fulminans linterae Sowerby, 1890 : 582 , pl. 56 fig. 12. Type locality: British Guiana , Mount Roraima; lectotype BMNH 1889.4.25.1 ( Breure 1978 ). Material. Guyana , Mount Roraima ( BMNH 1889.4.25.1/ lectotype , 1889.4.25.2/1 paralectotype , SMF 90007/ 1 paralectotype ); Ibidem, T. Pain leg., 1938 ( NMW .Z 1981.118.00303/3); Ibidem, 8000 ft [ 2438 m ], T. Pain leg., 1938 ( NMW .Z 1981.118.0 4142/1). British Guiana [= Guyana ] (ex Melvill Tomlin, NMW 1955.158.16700/1; ex Preston, RMNH /1). Remarks. The lectotype and paralectotype from the BMNH collection are figured here for the first time ( Figs 4 A─D). Although we do not precisely know where the type specimens were collected, we may infer from the locality given by Sowerby that it was on the slopes or base at the northeastern side of Roraima-tepui (R.W. McDiarmid, personal communication). Nonetheless, the material collected by T. Pain reveals that this is a highland species. The material also shows that there is some variation in expression of the columellar fold (in two specimens it is hardly noticeable) and in the colour of the lip (in three specimens dark liver coloured, in two other specimens whitish like in the type material). Plekocheilus (Plekocheilus) fulminans alticola Haas, 1955 ( Figs 4 E─G, 9 B) Plecocheilus (Plecocheilus) fulminans alticola Haas 1955 : 381 , fig. 81. Type locality: Venezuela , State of Bolívar, Chimantá massif, Torono tepui, on slopes bordering Caño Mojado, 2250 m ; holotype FMNH 52442. FIGURE 2. Genitalia in Plekocheilus (Eurytus) . A. P. (E.) t a te i Haas, 1955, FMNH 50346; B─D. P. (E.) huberi spec.nov. , UF 284746; E─F. P. (E.) nebulosus spec.nov. , UF 284723. Scale bar—5 mm. Material. Venezuela , Estado Bolívar, Chimantá massif, Toronó-tepui, slope bordering Caño Mojado, 2250 m , J.A. Steyermark leg., 21.ii.1955 ( FMNH 52442/ holotype , 52443/1 paratype ). Remarks. The oblique streaks on the ventral side of the last whorl make this form resemble Plekocheilus (Eurytus) juliani Haas, 1955 , but the different sculpture (malleation, Fig. 24B) and the darker colour of the peristome characterize this species. The colour pattern and the darker lip also distinguish this taxon from P. (E.) fulminans linterae .