Revision of the genus Spelaeoniscus Racovitza, 1907 with description of two new genera and four new species (Crustacea: Isopoda: Oniscidea)

On the basis of the study of a rich collection of Spelaeoniscidae from Sicily, the surrounding islands, the Maltese Archipelago and North Africa, collected during several faunistic expeditions, two new genera, Uncuniscus and Hybleoniscus, and four new species, Spelaeoniscus akfadouensis, Uncuniscus singularis, Uncuniscus elegans and Hybleoniscus vittoriensis, are described. The genus Spelaeoniscus Racovitza, 1907 is redefined and revised, and all species of the genus are briefly described and illustrated. Moreover, hypotheses on the differentiation process of the above genera and species are proposed based on their geographic distribution.