The new Ischnocolinae genus Catumiri
is described. The species Cenobiopelma argentinense
(Mello-Leitão, 1934), considered a junior synonym of Oligoxystre Vellard
, 1924, is transferred to the present genus. Three new species are also described: C. chicaoi
n. sp., from south of Bahia, Una; C. petropolium
n. sp., from Petrópolis, Rio de Janeiro (type species); and C. uruguayense
n. sp., from Lavalleja, Uruguay. Diagnosis, zoogeographical distribution and an identification key are provided for all species.