Two new species of Metacyclops are described from semi-terrestrial habitats in the Atlantic rain forest remnants along the coasts of the States of Sao Paulo and Rio de Janeiro, Brazil. Metacyclops oraemaris sp. n., found in moist moss, resembles M. paludicola from which it differs in the structure of leg 5 and the caudal rami. Metacyclops hirsutus sp. n.. a large species collected in leaf litter, is distinguished from its congeners also having a 12-segmented antennule, by a combination of characters in the caudal rami, leg 4 and maxilliped. The latter species also possesses a peculiar arrangement of cuticle striae and hairs on pedigers 2-5 and the genital double somite. The description of M. campestris Reid is emended. Differences in the armature of the antenna and maxilliped as well as in the arrangements and types of integumental pores of the urosome are pointed out as additional useful characters in the taxonomy of Metacyclops.