Language: Spanish with bilingual summary in English and French
The present study deals with a collection of Opiliones obtained from the Seychelles during the Belgian Expedition undertaken from 10th June till 31st August, 1972 by Prof. P.L.G. Benoit and J.J. van Mol. A general report of this expedition has been made by Benoit (1978). One hundred forty-two specimens of opilionids have been collected and seventeen species are found to occur on the Seychelles. One new genus and five new species are described. The already known species are listed among the newly collected ones. The species marked with one asterisk are those which have not been recorded during the Belgian Expedition, but of which the types have been studied; two asterisks indicate that the type has not been available for examination.
The already known species are redescribed and illustrations are given of the genitalia that had not been drawn so far. All the species belong to the suborder Laniatores and to one family, the Phalangodidae, which is represented by five subfamilies: Phalangodinae, lbaloninae, Pooloctinae, Samoinae and Biantinae. The Phalangodinae, though one of the most widespread subfamilies, are represented here by only a single species of the genus Metazalmoxis which is very closely related to Zalmoxis and which will probably be synonymized, pending more data on their status. The lbaloninae are represented by three genera: lbalonius, Holozoster and Sitalcicus. The first genus is the most common one. lts five "species" show some hybridization as there is no clear distinction between them. The genus Holozoster remains monotypical with the species H. ovalis whereas a new species is added to the genus Sitalcicus i.e. S. incertus a name referring to the problems encountered when placing the species.
The Samoinae are now represented by three genera: Mitraceras which is no longer monotypical as a new species, M. pulchra, is added, Samoa, recorded here for the first time with the new species S. sechellana and Benoitinus which is a new genus erected for the first blind Samoinae: B. elegans. The Biantinae are represented by three species in the genus Biantes; two were already known. The third one is the smallest opilionid known up to now. ‘The most striking characteristics of this opilionid fauna are its poverty with important faunistic lacunae and its complete endemism. The type with the bulk of the material studied are deposited in the collections of the "Koninklijk Museum voor Midden-Afrika". Some paratypes, as well as some duplicates, are kept in the author's collection.