Reviews of the genera Schaefferia Absolon, 1900, Deuteraphorura Absolon, 1901, Plutomurus Yosii, 1956 and the Anurida Laboulbène, 1865 species group without eyes, with the description of four new species of cave springtails (Collembola) from Krubera-Voronya cave, Arabika Massif, Abkhazia
Krubera-Voronya cave and other deep systems in Arabika Massif are being explored during many speleological expeditions. A recent Ibero-Russian exploration expedition (summer of 2010) took place in this cave with the aim of providing a study of the biocenosis of the deepest known cave in the world. Four new species of Collembola were found at different depths: Schaefferia profundissima n. sp., Anurida stereoodorata n. sp., Deuteraphorura kruberaensis n. sp., and Plutomurus ortobalaganensis n. sp., the last one at -1980 m deep. The identification and description of the new species have required the careful study of all congeneric species, implying a revision of each genus. As a result of this work tables and keys to all significant characters for each species are presented.