The genus Gibbocarina has been recently established and includes only two species (G. galeata and G. gracilis) characterized by presence of a hollow keel. Morphology and morphometry of Nebela penardiana from East Herzegovina were investigated based on 47 specimens and a new combination was proposed: Gibbocarina penardiana. In addition, morphological variability of a sympatric population of G. galeata was analyzed based on 121 specimens. It is possible to distinguish these species based on morphological and morphometric data. Morphometric analysis shows that shell width is one of the best discriminating characters (95–139 μm in G. galeata versus 64–77 μm in G. penardiana). The minimal variability was observed for shell length (5.17% in G. galeata and 4.44% in G. penardiana), while the maximal variability was recorded for area of the optical section (11.31% in G. galeata and 8.50% in G. penardiana).