The state of the art of Xyalidae (Nematoda, Monhysterida) with reference to the Brazilian records
Three species of the Trefusiidae Gerlach, 1966 are described from the Southern Bight of the North Sea. Trefusia litoralis (Allgén, 1932) is redescribed and information is given on the intraspecific variation. Trefusia curvispiculosa sp.nov. is characterized by its typically curved spicular apparatus, up to now not found in other Trefusia species. Rhabdocoma riemanni Jayasree & Warwick, 1977 is synonymized with Rhabdocoma americana Cobb, 1920 and that species is redescribed.