The genus Formosaurella Hirschmann, 1979 is resurrected with a new diagnosis and notes to the known two species. A new species of Formosaurella, F. tertiasp. nov., is discovered and described from Peru. The new species differs from the previously described ones in the shape of dorsal and ventral setae and the sculptural pattern of the sternal shield of the male and genital shield of the female. A new subgenus (Falcatanasubgen. nov.) is erected to accommodate Formosaurella (Falcatana) falcataHirschmann, 1972comb. nov. The new subgenus differs from the nominate subgenus in the shape of marginal setae, the shape of setae on posterior part of dorsal idiosoma, and the absence of a pygidial shield.