Shell variability of two Horatia species A–E H. ozimeci A sequenced specimen (2H76) B holotype OZRM 11603 C–E paratypes E NHMW 113607, (Photo NHMW by Ivo Gallmetzer) F–H H. stygorumina F holotype OZRM 11600 G–H paratypes NHMW 113608, (Photo NHMW by Gallmetzer) I Cf. Horatia knorri Schütt, 1961, spring of Ombla in Komolac, holotype SMF 164247 (Photo SMF by Sigrid Hof) J–P sequenced specimens of H. klecakiana J Vrelo Kosinac 2 K H. klecakiana, Gala spring L H. klecakiana, Ruda Beguša M, N, P H. klecakiana, Vrelo Kosinac 1 O H. klecakiana, Grabske Mlinice. The shell measurements are also shown: a shell height, b body whorl breadth, c aperture height, d spire height, e aperture breadth, α apex angle, β angle between body whorl suture and horizontal surface. Scale bars: 1 mm.