Spilotylenchus arthuri gen. n., sp. n. (Nematodea, Tylenchida: Allantonematidae) parasite of the European rabbit flea Spilopsyllus cuniculi (Dale, 1878) is described from a material including parasitic females so as freeliving adults, male and female. Neoparasitylenchus megabothridis Laumond et Beaucournu, 1977 and N. laplandicus Rubtzov et Darskaya, 1981, are held to belong to this new genus. S. arthuri produce a locking of the oogenesis in female fleas.