Abstract A body entirely covered with long and sharp-pointed spines makes Acanthoniscus spiniger Gosse, 1851, one of the rarest and most ornamented terrestrial isopods in the world. The original description of this species was based on a single specimen collected by the British naturalist Philip Henry Gosse in Jamaica in 1845 and deposited in the British Museum (currently The Natural History Museum, London). A second specimen, presumably of this species, was collected by the American entomologist Henry Guernsey Hubbard in 1877 and deposited in the United States National Museum, Smithsonian Institution, which served as the basis for a further description by Richardson (1909). After Gosse and Hubbard specimens, no additional material appears to have reached any museum collection. Due to the scarce available information on this genus, it has been indistinctly placed in at least four different families through history, without a consensus on its definitive placement to date. Herein, we describe a new species of Acanthoniscus Gosse, 1851, based on a population discovered in the Blue Mountains, Jamaica, above 1,200 m elevation and more than 150 km eastward of A. spiniger’s type locality. We also emend the authorship and diagnoses of the genus Acanthoniscus and its type species. Finally, we discuss the possible relationships of Acanthoniscus at the family level, concluding that, despite some putative autapomorphies, it belongs to Armadillidae, as its present-day status.

Three new species of Costa Rican schizomids belonging to the genus Surazomus Reddell & Cokendolpher, 1995, are described from Biological Station La Selva, Heredia province, and Biological Station Las Cruces, Coto Brus, Puntarenas province. Those additions raise to 16 the known nominal species of this genus and to nine the schizomid species recognized from Costa Rica.

Se describen tres especies nuevas de esquizómidos de Costa Rica que pertenecen al género Surazomus Reddell & Cokendolpher, 1995: una de la Estación Biológica La Selva, provincia Heredia; las otras dos, de la Estación Biológica Las Cruces, Coto Brus, provincia Puntarenas. Con estos nuevos aportes, se elevan a 16 los miembros del género y a nueve las especies de esquizómidos formalmente descritas de este país centroamericano.

A new species of the genus Rowlandius Reddell & Cokendolpher, 1995 is described from Sierra San Luis, Falcón State, northwestern Venezuela. Rowlandius arduus sp. n. may be characterized by having movable finger of chelicerae with a diminute sub-distal tooth, male with a poorly developed dorsal eminence on abdominal segment XII, and female with two pairs of weakly sclerotized, sinuous spermathecal lobes, without conspicuous terminal lobe. It is assigned to Rowlandius tentatively, because some characters are not congruent with this genus, nevertheless the absence of synapomorphic characters limits its inclusion in other one. This is the first record of the genus from Venezuela, and the third South American species described.

Se describe un nuevo esquizómido del género Rowlandius Reddell & Cokendolpher, 1995, proveniente de la Sierra de San Luis, Estado Falcón, en Venezuela noroccidental. Rowlandius arduus sp. n. se caracteriza por el dedo móvil del quelícero con un diminuto diente subdistal, una débil eminencia dorsoposterior en el segmento abdominal XII del macho y espermatecas constituidas por dos pares de lóbulos largos y sinuosos, tenuemente quitinizados, sin bulbo terminal notable. Su asignación al género Rowlandius es tentativa, pues posee varios caracteres que no concuerdan plenamente con el mismo, sin embargo la carencia de caracteres sinapomórficos limita su asignación a otro género. Este es el primer registro del género para Venezuela y la tercera especie suramericana conocida.