A REVISION OF THE GENUS POTOROSTRONGYLUS JOHNSTON AND MAWSON, 1939 (NEMATODA, CLOACINIDAE) FROM POTOROOS AND BETTONGS (MARSUPIALIA, POTOROIDAE), WITH THE DESCRIPTION OF 2 NEW SPECIES

Potorostrongylus finlaysoni, occurring in Potorous tridactylus and Bet tongia gaimardi, and P. aepyprymnus, occurring in Aepyprymnus rufescen s, are redescribed. Two new species, P. tropicus, occurring in B. trop icus, and P. temperatus, occurring in B. gaimardi, are described. P. t ropicus can be distinguished from P. aepyprymmus, the other species fo und in Queensland, by the wider terminal bulb of the oesophagus, in ha ving the dorsal lobe of the bursa longer than the lateral lobes rather than about the same length, slightly curved rather than markedly curv ed spicule tips, a larger number of appendages on the posterior lip of the genital cone, and a longer female tail and longer vagina compared with P. aepyprymmus. P. temperatus can be distinguished from P. finla ysoni, the other species occurring in Tasmania in having the dorsal lo be about the same length as the lateral lobes, rather than longer, the dorsal ray with longer rather than shorter lateral branches, the post erior lip of the genital cone with four pairs of setiform appendages r ather than the three pairs of bifid appendages, the vulva closer to th e anus and the vagina shorter compared with P. finlaysoni. A key to sp ecies of the genus is given.