Oligoxystre

Description. Chelicera without rastelum. Thoracic region slightly distinct. Eye tubercle weakly elevated, wider than long. Anterior row of eyes procurved; posterior row recurved. Labium much wider than long, with 2 – 10 cuspules. Maxilla with distinct anterior lobe with 14 – 35 cuspules on internal basal angle. Sternum oval, posterior sigilla marginal. Scopula on metatarsi: I – II entire for length, III – IV apical ¾ scopulated (except O. dominguense with metatarsi III and IV with scopula only for distal half). Tarsal scopula: I – III undivided; IV undivided with longitudinal band of setae. Superior tarsal claw without teeth. Inferior tarsal claw entirely absent. Tarsi without spines. Claw tufts well-developed. Posterior median spinnerets with 1 segment, very short. Posterior lateral spinnerets 3 - segmented, apical article digitiform. Spermathecae paired, longer than wide (except O. auratum with short, wide receptacula) with numerous termini. Male palpal bulb with thin embolus, straight or slightly curved, with small subapical keel in O. auratum and O. dominguense. Cymbium bilobed, longer than wide. Tibial spur formed by two well-developed branches. Species included: Oligoxystre auratum Vellard 1924, O. bolivianum (Vol 2001) n. comb, O. caatinga sp. nov., O. dominguense sp. nov, O. tucuruiense sp. nov, and O. rufoniger sp. nov.

Diagnosis. Differs from other ischnocoline genera but resembles Catumiri by the labium being much wider than long and having a reduced number of cuspules (fewer than 10). Differs from Catumiri by the undivided tarsal scopula on I – III and scopula on tarsi IV undivided but with a longitudinal band of setae that does not divide the scopula, by the metatarsus I having scopula ventrally for its length, by the spermathecae with numerous termini, by the well-developed retrolateral branch of the tibial spur, and by tarsal claws of males without teeth. Type-species: Oligoxystre auratum Vellard 1924, by original designation.