Frenopyxis stierlitzi gen. nov., sp. nov. - new testate amoeba (Amoebozoa Arcellinida) from the urban parks with notes on the systematics of the family Centropyxidae Jung, 1942 Author Bobrov, Anatoly Lomonosov Moscow State University, Leninskiye gory 1, Moscow, Russia, 119991 & anatoly-bobrov @ yandex. ru; https: // orcid. org / 0000 - 0003 - 2240 - 384 X Author Mazei, Yuri Lomonosov Moscow State University, Leninskiye gory 1, Moscow, Russia, 119991 & Severtsov Institute of Ecology and Evolution, Leninskiy ave. 33, Moscow, Russia, 117071 text Zootaxa 2020 2020-11-26 4885 3 384 394 journal article 9478 10.11646/zootaxa.4885.3.4 c54f0533-c65e-4007-acda-5eb84ad4a321 1175-5326 4296751 9757A8EF-A2F5-41C7-BFFC-DABFEA377B30 Frenopyxis gen. nov. Description. Shell bilaterally symmetrical, broad elliptic, sometimes almost circular, dorsoventrally flattened, yellowish to colorless; aperture is placed slightly eccentrically on a ventral part of a shell at the bottom of a wide funnel (invagination); aperture usually drop-shaped with narrow side oriented toward closest side; sometimes aperture circular. There is an internal thick organic lip surrounding an aperture and continuing in a bridle, which connects an aperture with the internal side of a shell wall and broaden in the place of connection of a bridle and a shell wall. Etymology. The name of new taxon reflects its most characteristic feature, i.e. bridle (from Latin— Frenum ). Type species. Frenopyxis stierlitzi sp. nov. Related genera. New genus differs from the type genus of the family Centropyxis Stein, 1857 by an internal thick organic lip surrounding an aperture and continuing in a bridle, which connects an aperture with the internal side of a shell wall and broaden in the place of connection of a bridle and a shell wall. New genus differs from the genus Armipyxis Dekhtjar, 2009 by luck of internal transversal diaphragms with circular openings, which subdivide internal shell volume into two parts; internal bridle of the new genus connects aperture and shell wall (as in Armipyxis ) but does not subdivide the shell into separate sections.