Description of two new Ecuadorian Zilchistrophia Weyrauch, 1960, with the clarification of the systematic position of the genus based on anatomical data (Gastropoda, Stylommatophora, Scolodontidae)

Shells of Zilchistrophia Weyrauch, 1960 species. A Holotype of Zilchistrophia tridentata Weyrauch, 1960 (SMF 162006; type species of the genus), arrow shows the inflated part of the last whorl B holotype of Zilchistrophia hilaryae sp. n. (NHMUK 20020375.1), arrow shows the non-inflated part of the body whorl C paratype of Z. hilaryae sp. n. (subadult shell with the last quarter of whorl removed in order to show palatal plicae) D holotype of Zilchistrophia shiwiarorum sp. n. (NHMUK 20020382) E plicae bearing shell fragment of the anatomically examined specimen of Z. hilaryae sp. n. (arrows indicate the plicae) F plicae bearing shell fragment of the anatomically examined specimen of Z. shiwiarorum sp. n. (arrows indicate the plicae). The two shell fragments (E and F) are left together with the ethanol-preserved body. Scale represents 5 mm, and refers to A, B and D.