Three new species of the spider genus Plato and the new genus Cuacuba from caves of the states of Pará and Minas Gerais, Brazil (Araneae, Theridiosomatidae)

Abstract. Three new species of the genus Plato from caves in the states of Pará and Minas Gerais, Brazil, are described. P. novalima sp. n., from Minas Gerais, is the first record of the genus in the southeastern region of Brazil. P. ferriferus sp. n. and P. striatus sp. n., from Carajás, Pará, north of Brazil, are also described. The former is an extremely abundant species, whereas the latter has only one known male specimen. Cuacuba gen. n. is proposed and represented by two new species, C. mariana sp. n. (type species) and C. morrodopilar sp. n., both from the state of Minas Gerais. Morphology of genitalia in Cuacuba gen. n. is similar to other Theridiosomatidae genera and is herein discussed. None of the proposed species presents troglomorphic adaptations. They are widespread, abundant inside caves in different and large karst areas, and each genus prefers different lithologies.