Dragonflies (Odonata) From The Sierras Of Tapirapeco And Unturan, In The Extreme South Of Venezuela Author DeMarmels, Jurg text Acta Biologica Venezuelica 1992 14 1 57 78 journal article 10.5281/zenodo.3266063 39c9ce8d-d95d-467e-9590-ab184d952201 3266063 Oxystigma williamsoni Geijskes, 1976 Material. 3♂ , 5 ♀ , Base Camp