Freeliving nematodes from nature reserves in Costa Rica. 1. Dorylaimina

This article gives the first results of a study of dorylaims found in natur e reserves in Costa Rica. The material examined shows the great interest of the nematofauna of these reserves. Two species were found for which new ge neric names had to be erected: Parapalus n.gen. for a species resembling Pa raxonchium but with a long symmetrical odontostyle as in Gopalus the single species P. arboricola n.sp. lives in epiphytic mosses. Inbionema n.gen. is conspicuous for the very widely separate lips and the long (but not needle -shaped) odontostyle; the single species I. biforme n.sp, (named because th ere are two classes of odontostyle length, under 44 and over 59 mum) lives in the same habitat as the previous species. Other new species found are: P achydorylaimus schizodontus n.sp. (furcate part eel 33% of odontostyle leng th), Sicorinema esquiveli n.sp. (cuticular annules 0.5 Crm wide, body lengt h over 1 mm): Brasilaimus bidentatus n.sp. (24-26 longitudinal ridges, each onchium with an additional denticle), B. vinciguerrae n.sp. (32 ridges, od ontostyle slender), Xiphinemella monyhystera n.sp. (female monodelphic, tai l conoid in both sexes) and Tyleptus bongersi n.sp. (liplets amalgamated in to disc-like structure, distance vulva-cardia very short). The female of Id iodorylaimus annulatus (von Daday, 1905) is reported for the first time. Th e following nominal species were found and redescribed: Practinocephalus se cundus Andrassy, 1986, Axonchium labiatum Thorne, 1939, Metaxonchium micans (Thorne, 1939), Oxydirus tropicus Theme, 1964, O. tenuicaudatus Theme, 196 4, Funaria acuta (Zullini, 1973), Caveonchus saccutus (Goseco et al., 1981) and Sclerostylus xiphinemoides (Monteiro, 1970). A key to the species of P achydorylaimus is given. The subfamily Paraxonchiinae and the position of t he genus Gopalus are discussed.