Revision of the genus Parvirostrum Fuhrmann, 1908 (Cestoda: Cyclophyllidea: Paruterinidae).

Redescriptions are presented of the type-materials of Parvirostrum reticulatum Fuhrmann, 1908 (type-species of Parvirostrum Fuhrmann, 1908) from Lepidocolaptes albolineatus (Passeriformes: Dendrocolaptidae) and of P. synallaxis (Mahon, 1957) n. comb. (syn. Deltokeras synallaxis Mahon, 1957) from Synallaxis rutilans (Passeriformes: Furnariidae), both from Brazil. P. linusi n. sp. is described from Dendrocolaptes platyrostris (Dendrocolaptidae) from Paraguay. It is characterised by a strobila up to 29 mm long, 50-56 triangular rostellar hooks (13-15 microm long) in two regular rows, irregularly-alternating genital pores, the variable position of the genital ducts relative to the osmoregulatory canals, 11-17 testes, a cirrus-sac 104-129 microm long, a cirrus armed with minute spines, elongate gravid proglottides and a uterine development which initially passes through a sac-like stage, followed by a sac-like stage with diverticula and finally through a reticulate stage. An incomplete description of Parvirostrum sp., based on contracted specimens from Lepidocolaptes angustirostris from Paraguay, is presented. The diagnosis of Parvirostrum is amended.