Redefinition of Holosticha Wrzesniowski, 1877 (Ciliophora, Hypotricha)

A revision of the urostylid hypotrichs showed that at present Holosticha is characterized by an unspecified combination of plesiomorphies. Thus more than 100 species have been originally described in this genus, and about 49 species are currently recognised. However, a detailed comparison of the descriptions showed that Holosticha comprises only 7 species unified by a highly characteristic combination of apomorphies (e.g. anterior end of left marginal row curved rightwards, adoral zone bipartite, buccal cirrus distinctly ahead of paroral) and plesiomorphies. The other species at present included in Holosticha are assigned to Anteholosticha nov. gen. (29 species), Caudiholosticha nov. gen. (10 species), and Biholosticha nov. gen. (2 species).