Systematic review of the genera Rhabdostyla Kent 1880 and Orborhabdostyla Foissner et al. 2010 (Ciliophora, Peritrichia, Epistylididae) Author Souza, Pedro Mendes De ¹ Laboratório de Protozoologia, Programa de Pós-Graduação em Biodiversidade e Conservação da Natureza, Universidade Federal de Juiz de Fora, Martelos, 36036 - 900, Juiz de Fora, Brazil Author Rossi, Mariana Fonseca ¹ Laboratório de Protozoologia, Programa de Pós-Graduação em Biodiversidade e Conservação da Natureza, Universidade Federal de Juiz de Fora, Martelos, 36036 - 900, Juiz de Fora, Brazil Author Dias, Roberto Júnio Pedroso ¹ Laboratório de Protozoologia, Programa de Pós-Graduação em Biodiversidade e Conservação da Natureza, Universidade Federal de Juiz de Fora, Martelos, 36036 - 900, Juiz de Fora, Brazil text Zootaxa 2024 2024-01-12 5399 3 201 230 http://dx.doi.org/10.11646/zootaxa.5399.3.1 journal article 10.11646/zootaxa.5399.3.1 1175-5326 10516774 2134D857-542C-40A6-9557-CB8E042E4271 Rhabdostyla tritora ( Nenninger 1948 ) nov. comb. — Fig. 4 , O’ Opisthostyla tritora Nenninger, 1948: 178 , pl. 12, fig. a, b Diagnosis: Size about 180 µm long and 200 µm wide. Body wider than tall, almost spherical. Portion of the body closest to the peduncle is extremely narrow. Peduncle with 1/6 of the body’s length. Peristomial disc surrounded by two ciliary chains. Peristomial collar divided into 3 thin layers. Peristomial disc and collar rest on the body like a lid. Infundibulum, which is almost straight, reaches half the length of the body. Contractile vacuole at the end of the infundibulum. Cytoplasm contains coarse grains, except for the tapered end that precedes the peduncle. With several food vacuoles containing dark granulations. Difficult to visualize macronucleus, in the form of a “worm”, thick and curved, positioned transversely in the middle of the body. Found in the coastal zone of Regnitz, on annelids, Helobdella stagnalis , and algae, Ceratophyllum . Remarks: diagnosis according to Nenninger (1948) .