All genera and species from Europe and the Mediterranean are diagnosed or redescribed, differentiating characters are illustrated and an identification key is provided. A review of literature and biological information is included, and a classification, with two new genera, is proposed. The superfamily Axioidea comprises the Axiidae, with Axius stirhynchus, Calocarides coronatus, Levantocaris hornungae; and the Calocarididae with Calastacus laevis and Calocaris macandreae. The Callianassoidea include the Callianassidae, Ctenochelidae, Laomediidae and Upogebiidae. The Callianassidae contain three subfamilies. The Callianassinae have three species placed in Callianassa: C. acanthura, C. subterranea and C. truncata; three other species are assigned to a new genus, Pestarella n. gen.: P. candida n. comb., P. tyrrhena n. comb. and P. whitei n. comb. Pestarella n. gen. species have an operculiform Mxp3, a telson rounded in posterior half, and no Plp1-2 in male. The little known species Calliapagurops charcoti is placed in the Callichirinae. The Eucalliacinae contain two species: Calliax lobata and Calliaxina punica n. comb., type species of a new genus, Calliaxina n. gen. Species of Calliaxina n. gen. possess a rostrum with pointed tip, an operculiform Mxp3 with exopod, the P1 equal and similar, and Plp1-2 with appendix interna in both male and female. The Ctenochelidae have one subfamily, Gourretinae with Gourrretia denticulata. The Laomediidae are represented by one species, Jaxea nocturna, and the Upogebiidae by seven species: Gebiacantha talismani, Upogebia deltaura, U. mediterranea, U. nitida, U. pusilla, U. stellata and U. tipica.
Crustacea, Decapoda, Thalassinidea, Europe, Mediterranean, new genera, revision.