O estudo dos nematóides das ordens Tylenchida (sensu MAGGENTI et al., 1987) e Dorylaimida (famílias Longidoridae e Trichodoridae), obtidos de 210 amostras de solo de rizosfera, processadas pelo método de JENKINS ( 1964), e raízes de 32 espécies de plantas, processadas pelo método do Funil-de-Baermann (FLEGG & HOOPER, 1970), de 21 municípios do Rio Grande do Sul, Brasil, revelou a ocorrência de 8 espécies ainda inominadas (Dolichodorus sp., Tylenchorhynchus sp. “A”, Tylenchorhynchus sp. “B”, Heiicotylenchus sp., Criconema sp. “A” e Criconema sp. “B”. Criconemella sp., e Discocriconemella sp.) e de 37 espécies já conhecidas da Ciência (Tylenchus davainei, Cephalenchus leptus, Coslenchus alacinatus, Psilenchus hilarulus, Ditylenchus dipsaci ( * ), Triversus hollisi, Pratylenchus brachyurus ( * ), P. zeae ( * ), P. scribneri ( * ), Radopholus similis, Hoplolaimus galeatus, Aorolaimus perscitus, Helicotylenchus dihystera ( * ), H. crenacauda, Rotylenchus caudaphasmidius, Scutellonema brachyurus, S. bizanae, Meloidogyne exígua, M. incógnita ( * ), M. javanica ( * ), Criconema demani, Criconemella palustris, C. reedi, C. sphaerocephala, C. xenoplax, Hemicriconemoides minutus, Ogma civellae, Hemicycliophora poranga, H. ripa, H. tenuistriata, Caloosia paradoxa, Paratylenchus aquaticus, Aphelenchus avenae (*), Aphelenchoides besseyi ( * ), Xiphinema californicum, X. krugi e Paratrichodorus minar). Destas últimas, somente nove (as marcadas com asterisco) já haviam sido relatadas para o Rio Grande do Sul. Sinônimos, resultados da mensuração, observações sobre a morfologia (ou descrição, diagnose e desenhos para as espécies inominadas) e ocorrências (locais e plantas associadas) são apresentados para cada espécie

The study of nematodes of the orders Tylenchida ((sensu MAGGENTI et al., 1987) and Dorylaimida (families Longidoridae and Trichodoridae), recovered from 210 samples of soil around roots by Jenkins technique and from roots by Baermann-funnel technique, collected in 21 counties of the State of “Rio Grande do Sul”, Brazil, resulted in the records of eight innominate species (Dolichodorus sp., Tylenchorhynchus sp. “A”, Tylenchorhynchus sp. “B”, Heiicotylenchus sp., Criconema sp. “A”, Criconema sp. “B”, Criconemella sp. and Discocriconemella sp.) and of 37 species already known by Science (Tylenchus davainei, Cephalenchus leptus, Coslenchus alacinatus, Psilenchus hilarulus, Ditylenchus dipsaci( * ), Triversus hollisi, Pratylenchus brachyurus ( * ), P. zeae ( * ),P. scribneri ( * ), Radopholus similis, Hoplolaimus galeatus, Aorolaimus perscitus, Helicotylenchus dihystera ( * ), H. crenacauda, Rotylenchus caudaphasmidius, Scutellonema brachyurus, S. bizanae, Meloidogyne exígua, M. incógnita ( * ), M. javanica ( * ), Criconema demani, Criconemella palustris, C. reedi, C. sphaerocephala, C. xenoplax, Hemicriconemoides minutus, Ogma civellae, Hemicycliophora poranga, H. ripa, H. tenuistriata, Caloosia paradoxa, Paratylenchus aquaticus, Aphelenchus avenae ( * ), Aphelenchoides besseyi ( * ), Xiphinema californicum, X. krugi, and Paratrichodorus minar). These, except the nine ones with asterisk, are new records for the State of "Rio Grande do Sul". Junior synonyms for the species, mean and range of measurements, morphological variations of the known species or descriptions, diagnoses and drawings of innominate species, hosts and localities of samples are given