OSWALDOCRUZIA (NEMATODA, TRICHOSTRONGYLIN A, MOLINEOIDEA) PARASITIC IN BRAZILIAN AND ECUADORIAN AMPHIBIANS, WITH REDEFINITION OF THE TYPE SPECIES OSWALDOCRUZIA-SUBAURICULARIS (RUDOLPHI, 1819) AND OSWALDOCRUZIA-MAZZAI (TRAVASSOS, 1935)

O. subauricularis (Rudolphi, 1819), type species of Oswaldocruzia Trav assos, 1937, parasite from Brazilian and Ecuadorian Bufonidae and O. m azzai Travassos, 1935, parasite from Argentinian Bufonidae are redescr ibed using new morphological characters, particularly the relative arr angement of the bursal rays 6,8 and 9 and the pattern of the synlophe in the oesophagal region. Oswaldocruzia dlouhyi n.sp. coparasite of O. subauricularis from Bufo sp. and Oswaldocruzia taranchoni n.sp. fom B ufo marinus are described from Brasil. O. dlouhyi belongs to the Oswal do-cruzia species group having cervical alae and rays 8 arising on the dorsal ray and overlapped by rays 6 along their median part (type II) . The species is characterised by a cephalic vesicle in two parts and by rays 4 longer than rays 5. O. taranchoni belongs to the Oswaldocruz ia species group having no cervical alae and rays 8 arising on the roo t of the dorsal ray and joined to rays 6 along the two thirds (type II I). The species is characterised by a cephalic vesicle in one part, by the spicular externo-lateral branch (blade) not divided on its tip an d by rays 8 joined to the common trunk of rays 4 to 6. With just one e xception, the neotropical Oswaldocruzia have spicula divided in three main branches: blade, shoe and fork as is the case in holarctic Oswald ocruzia but the division of the fork always occurs before the distal t hird of its length in neotropical species and beyond the distal third in holarctic ones. A new taxon is proposed: Oswaldocruzia proencai n.s p.(= O. mazzai sensu Lent et al., 1946 nec Travassos, 1935).