In this paper, Trechona venosa rufa Vellard 1924 is elevated to species rank, a neotype is designated, the male is described for the first time, and the female is redescribed. Trechona rufa seems to be restricted to the Atlantic Forest of São Paulo state, southeastern Brazil, covering an area along the coast and going up to the southern slope of the Mantiqueira mountain chain. The composition and distribution of the genus Trechona is changed. As a result, only three valid species remain in Trechona, all inhabiting the Atlantic Forest of Brazil. The other species formerly included in Trechona are considered below: T. lycosiformis (C.L. Koch 1842)  =  Avicularia lycosiformis comb. nov., Theraphosidae incertae sedis; T. sericata (Karsch 1879)  =  Linothele sericata (Karsch 1879), Dipluridae incertae sedis; T. adspersa Bertkau 1880  =  Nemesiidae incertae sedis; T. rogenhoferi (Ausserer 1871)  =  nomen dubium.