2016AbstractIn this detailed electron microscopic study of Paradermamoeba levis Smirnov et Goodkov 1994 (phylum Amoebozoa, classDiscosea, subclass Longamoebia, order Dermamoebida, family Dermamoebidae) based on numerous fixations and studies ofa large number of cells we provide the first comprehensive description of the ultrastructure of this species. P. levis possessescytoplasmic microtubule-organizing centres (MTOCs) associated with dictyosomes of the Golgi complex. This finding addsevidence to our earlier suggestion that the presence of cytoplasmic MTOCs is a synapomorphy of the phylogenetic lineagesforming the subclass Longamoebia. The so-called “supernumerary nucleus” of P. levis noted in the initial description was foundto be not an individual structure but an outgrowth of the cell nucleus containing its own nucleolus. Enigmatic trichocyst-likebodies were noted in all studied strains, originating from different geographic locations. This proves that these bodies are integralparts of the cell structure, not an occasional property of the type strain. P. levis is now reliably recorded from several Europeanlocations (North-Western Russia, Croatia, Switzerland, UK) and Far East of Russia.© 2016 Elsevier GmbH. All rights reserved.