The spider family Filistatidae is represented in Argentina by at least twelve species. The synanthropic and apparently introduced Kukulcania hibernalis (Hentz) is the only representative of the Filistatinae. The remaining species all belong to Prithinae. Two new prithine genera are described: Lihuelistata is erected for Filistata metamerica Mello-Leitão, and Misionella is erected for Filistata mendensis Mello-Leitão. Pikelinia Mello-Leitão is represented by P. tambilloi (Mello-Leitão), P. patagonica (Mello-Leitão), newly transferred from Malalistata, and seven new species: P. colloncura, P. mahuell, P. roigi, P. kolla, P. ticucho, P. toba and P. puna. The genus Malalistata Mello-Leitão is newly synonymized with Pikelinia. Filistata fasciata Banks, is transferred to Pikelinia. A cladistic analysis of filistatid genera is made, based on a data matrix of 13 terminals scored for 29 characters. Pikelinia, Lihuelistata and Misionella form a monophyletic group united by the partial fusion of cymbium and tegulum and the incrassate male palpal tibia. The resulting cladogram conflicts with a previous hypothesis of relationships only on the placement of Filistatinella. The morphology of posterior respiratory system of filistatids is examined, and its connections with abdominal muscles elucidated. On that base, it is demonstrated that the remnants of posterior respiratory system of prithines are homologous of entapophyses (muscular apodemes) instead of book-lungs.