The present report is related to an oxyurid nematode recovered from a reptilian host, Mabuya frenata (Cope, 1862) and the proposal of Skrjabinodon helicostai sp.n., based mainly on findings referring to the lateral alae, position of excretory pore and vulvar apertures, cuticular spines of the tail and aspect of the eggs. The examination of types of Skrjabinodon capacyupanquii (Freitas, Vicente & Ibanez, 1968) from a Peruvian lizard, indicated the reallocation of this species in the genus Thelandros Wedl., 1862, as T. capacyupanquii comb.n., based on the diameter of the caudal appendage of males and position of the vulvar aperture. The new species described herein represents the first report of a species of the genus Skrjabinodon Inglis, 1968 in South America.

De 149 autópsias realizadas em peixes, os autores coletaram diversos helmintos, no litoral de Macaé, Estado do Rio de Janeiro, Brasil. A maior parte das espécies aqui estudadas, são redescritas, algumas apenas referidas e uma nova espécie do gênero Rhipidocotyle Diesing, 1858, é descrita nesta oportunidade.

From 149 fishes examined the authors obtaied several helminths in Macaé Coast, Rio de Janeiro State, Brazil. A new species is presently described and some only refered. The helminths were recovered from February, 1970, to December, 1971. The authors give general parasitism by helminthic groups and the percentage is calculated based only on the infested fishes. In preceding papers the authors had described two new species, that here are only refered: Procamallanus macaensis Vicente & Santos, 1972 and Pulchrascaris caballeroi Vicente & Santos, 1972. the new species now enclosed is Rhipidocotyle fluminensis sp. n. Sterrhurus imocavus Looss, 1907 and Cucullanus cirratus Mueller, 1777 are given to be new host record and new geographical distribution. Pleorchis mollis Poche, 1926, Lecithochirium microstomum Chandler, 1935, Homalometron longulum Travassos, Freitas & Buhrnheim, 1965, Porrocaecum secundum Chandler, 1935 are also new host records. The authors give original camera lucidan drawings of some of the species here presented.