Key to Species of Tridysderina 1. Sternum with second transverse ridge at level of coxa III (fig. 346)........................ bellavista – Sternum with single transverse ridge at level of coxa II (fig. 302)..........................................2 2. Males (those of T. archidona and T. tena unknown).................................................................3 – Females.............................................................................................................................................5 3. Embolus widest at tip (fig. 310)........................................................................................... yasuni – Embolus widest before tip.............................................................................................................4 4. Tip of conductor reaching to near tip of embolus (fig. 321)............................................ jatun – Tip of conductor not reaching to near tip of embolus (fig. 332).................................. galeras 5. Apodemes long (fig. 312)..................................................................................................... yasuni – Apodemes much shorter................................................................................................................6 6. Anterior genitalic projection protruding anterior of anterior margin of genitalic atrium (figs. 339, 340).................................................................................................................. archidona – Anterior genitalic projection shorter............................................................................................7 7. Anterior margin of genitalic atrium rounded (figs. 323, 324).......................................... jatun – Anterior margin of genitalic atrium squared (figs. 335, 345)..................................................8 8. Posterior margin of transverse bar connecting apodemes prolonged along midline (fig. 335).......................................................................................................................................... galeras – Posterior margin of transverse bar connecting apodemes not prolonged along midline (fig. 345)...................................................................................................................................... tena

Published as part of Platnick, Norman I. & Berniker, Lily, 2013, The South American goblin spider genera Dysderina and Tridysderina (Araneae, Oonopidae), pp. 1-52 in American Museum Novitates 2013 (3772) on pages 46-47, DOI: 10.1206/3788.1, http://zenodo.org/record/10109373