Phylogenetic position of the relict South American genus Idiopyrgus Pilsbry, 1911 (Gastropoda, Truncatelloidea), with the description of two new cave species

Shells of Idiopyrgus spp. A, B. I. souleyetianus Pilsbry, 1911, holotype ANSP 100534; C, D. I. pilsbryi Baker, 1914, lectotype ANSP 130700; E. I. walkeri Pilsbry, 1924, reproduced from Pilsbry (1924: p. 6, fig. 9); F, G. I. rudolphi (Hass, 1938), holotype SMF 24365; H. I. brasiliensis (Rey, 1959), reproduced from Rey (1959: p. 145, fig. 2). Scale bars: 1 mm.