The genus Murunducaris, previously represented by a single species (M. juneae) collected in a hillside flush marsh near Brasília, Brazil, is revised here. The description of M. juneae is emended. Three additional species are assigned to the genus, and its geographical distribution is considerably expanded. Murunducaris noodti n. sp., from the vicinity of Arequipa (Peru), and M. loyolai n. sp., from the island of the city of Florianópolis (Santa Catarina, Brazil) are new to science. Murunducaris dactyloides (formerly Parastenocaris dactyloides), from the Tapajós River, near the city of Santarém (Pará, Brazil) is redescribed and its assignment to this genus is supported by synapomorphies. The diagnosis of the genus Murunducaris is emended. The phylogenetic affinities of species of Murunducaris to other members of the family are briefly discussed.