Three previously described and one new species are treated. M. amazonicus sp. nov. from the Brazilian Amazon Basin and the Pantanal is described from pupal exuvia and four adult females. M. barrettoi Fairchild, 1969 and M. muscoideus (Hine, 1907) are redescribed from lectotypes, here designated, and M. sarcophagoides Lutz, 1928 is redescribed from holotype. An illustrated key for female adults and for known pupae species are provided.
Amazon Basin; horseflies; taxonomy
