The Shannoni complex, comprising sand flies belonging to the subgenus Psathyromyia (Psathyromyia) Barretto, consists of several species, of which the females have banana-shaped spermathecae and the males have digitiform parameres on the terminalia. Among these species, Psathyromyia shannoni (Dyar) and two taxa considered as its junior synonyms (Phlebotomus limai Fonseca and Phlebotomus bigeniculatus Floch & Abonnenc), Psathyromyia pestanai (Barretto & Coutinho), and a new species are the focus of this study. On the basis of morphological and morphometric characters, Psathyromyia bigeniculata (Floch and Abonnenc) stat. rev.; comb. n. and Psathyromyia limai (Fonseca) stat. rev.; comb. n. are resurrected from the synonymy of Pa. shannoni. Pa. pestanai is proposed as a new junior synonym of Pa. limai. Psathyromyia ribeirensis sp. n., occurring in the middle and upper Ribeira Valley in the state of São Paulo, Brazil is described. Pa. limai, described from the Serra da Cantareira (São Paulo municipality) and also found in the lower Ribeira Valley and on the adjacent coastal plain, is morphologically very close to the new species.