A DESCRIPTION OF GRAPHIDIOIDES-KRAVETZI N-SP AND THE REVISION OF GRAPHIDIOIDES CAMERON, 1923 (NEMATODA TRICHOSTRONGYLOIDEA), PARASITES OF NEOTROPICAL RODENTS

Graphidioides kravetzi n. sp., from the cricetid Holochilus brasiliens is in Uruguay, is characterised by relatively long rays 2 in relation to the length of rays 3 and by the characters of the synlophe: the sam e number of ridges at mid-body and at the level of oesophago-intestina l junction; and in the anterior part of the body ridges facing the lat eral fields more developed than the others at the same level. Redescri ptions of three species belonging to the genus Graphidioides Cameron, 1923 (Trichostrongylinae) from Argentina are presented: G. rudicaudatu s (Railliet and Henry, 1909) Cameron, 1925 from Lagostomus maximus; G. mazzai Lent and Freitas, 1935 from Cavia aperea pamparum; and G. tagl ei Babero and Cattan, 1975 from Octodon bridgesi. Complementary data a re provided concerning the type-species, G. affinis (Megnin, 1895), fr om Dolichotis patagonum. An amended definition of the genus Graphidioi des is proposed, mainly based on a knowledge of the synlophe, with rid ges orientated perpendicularly to the body surface and lacking facing the lateral cords, and the pattern of the caudal bursa. A dichotomous key to the species of the genus is provided.