Opiliones (Arachnida) de la Reserva Histórica de Santa Catalina (Buenos Aires, Argentina) y sus implicancias biogeográficas

two species of opiliones have been found in the santa catalina historical reserve (buenos aires, argentina), holmbergiana weyenberghii (holmberg) (eupnoi, sclerosomatidae, gagrellinae) and discocyrtus prospicuus (holmberg) (laniatores, gonyleptidae, pachylinae). both species are associated with celtis ehrenbergiana woods and hygrophilous woods along all the coast of the la plata river, so they belong to the mesopotamic opiliological area. the historic reserve of santa catalina is not near the river coast, and because of this the santa catalina forests is considered as a refuge of an historical distribution of the mesopotamic opiliones, being an extension or fingering of their natural distribution following the matanza-riachuelo rivers hydrological system. in addition, data about the natural history of both species is offered.