Abstract Phoxocephalopsids are fossorial amphipods endemic to the Southern Hemisphere and currently encompass five genera and 15 species, including the four new species herein described. Previous records of the family along the Brazilian coast are limited to Phoxocephalopsis zimmeriSchellenberg, 1931. Based on material from the Crustacean Collection of Museu Nacional/UFRJ four new species of Phoxocephalopsidae areherein described: Phoxocephalopsis ruffoi sp. nov. from Rio de Janeiro, São Paulo, Paraná and Rio Grande do Sul (23o-30oS); Puelche irenae sp. nov. from Espírito Santo and Rio de Janeiro (19o-23oS); Puelche longidactylus sp. nov. from Bahia, Espírito Santo and Rio de Janeiro (12o-23oS) and Puelche mourae sp. nov. found only at Rio de Janeiro. High diversity was recorded from the Campos Basin region, which extends from the north of Rio de Janeiro to south of Espírito Santo (21o-23oS), with the presence of all four phoxocephalid species. A key to Phoxocephalopsidae species from Brazil, including P. orensanziBarnard and Clark, 1982 is provided.

ABSTRACT The family Talitridae Rafinesque, 1815 is the only group, among the amphipods, that colonized the terrestrial environment, and more than half of its species live in tropical and subtropical forests. Nowadays, the family has approximately 270 species described in 64 genera. Leaf litter samples from Atlantic forests and urban areas of the states of Rio de Janeiro, São Paulo, Minas Gerais, Paraná, Santa Catarina, and Rio Grande do Sul, provided material to redescribe the two terrestrial species known to Brazil, Talitroides alluaudi (Chevreux, 1896) and Talitroides topitotum (Burt, 1934), and enlarge their known distribution. These species have a worldwide distribution, as they are commonly dispersed in a synanthropic way. Talitroides topitotum seems to be well established in Brazilian Atlantic forests: 96% of the 1787 individuals examined (51 samples) corresponded to this species. Also, females dominated the samples and only six males were found: four from T. alluaudi and two from T. topitotum. A detailed comparison of these two species, as well as their geographical distribution, is given.

The lysianassoid species Eurythenes thurstoni Stoddart & Lowry, 2004 is recorded for the first time to the Southern Atlantic Ocean, with material collected from the South Mid-Atlantic Ridge during the MAR-ECO Project expeditions. The examined material presents some important variations when compared with the original description discussed in the text.

La especie lisianásida Eurythenes thurstoni Stoddart & Lowry, 2004 se registra por primera vez en el océano Atlántico sur, con el material colectado en la Cordillera Mesoatlántica Sur durante las expediciones del Proyecto MAR-ECO. El material examinado presenta algunas variaciones importantes en comparación con la descripción original, que se discute en el texto.