European and Mediterranean Thalassinidea (Crustacea, Decapoda) Author Ngoc-Ho, Nguyen Muséum national d’Histoire naturelle, Département Milieux et Peuplements aquatiques, 61 rue Buffon, F- 75231 Paris cedex 05 (France) nngoc-ho @ mnhn. fr. ho@mnhn.fr text Zoosystema 2003 25 3 439 555 journal article 10.5281/zenodo.5402949 1638-9387 5402949 Family AXIIDAE Huxley, 1879 TYPE GENUS . — Axius Leach, 1815 , by original designation. REMARKS Recent major works dealing with axiids include: Sakai & de Saint Laurent 1989 ; Kensley 1989 ; Poore 1994 (as part of the phylogeny of the Thalassinidea families); Sakai 1994 . Examination of European materials supports the view of Kensley (1989) and Poore (1994) rather than those of Sakai & de Saint Laurent (1989) and Sakai (1994) in resurrecting the family Calocariidae Ortmann, 1891 . In this family of hermaphrodites, the appendix masculina is presumably fused to the median portion of the Plp2 endopod which is densely setose or spinose mesially. The distal portion of the Plp2 endopod is large, and similar to that of the exopod, in Calocaris macandreae ( Fig. 7D ); it is less defined in Calastacus laevis ( Fig. 5I ). This work does not give as much importance as did Sakai & de Saint Laurent (1989) to the thoracic sternite of P4 since its morphology does not vary much in the species studied, except for the presence of a spine on the lateral border ( Fig.1I ), and in its size. These are indicated in the diagnosis. A species probably not belonging to the European fauna but often mentioned in the past, Coralaxius nodulosus ( Meinert, 1877 ) (better known as Axius nodulosus Meinert, 1877 ), is briefly treated.