Protoperidinium crassipes (Kofoid) Balech 1974. Rev. Mus. Argent. Cienc. Nat. “ B. Rivadavia ”, Hydrobiologia 4 (1): 60. (Figs. 13, 16). References: Paulsen 1907: 58; Abé 1927: 408, Figs. 26–27; Schiller 1937: 223, Fig. 220 a–p; Kiselew 1950: 192, Figs. 323 a–v, 328 a–i; Wood 1968: 99, Fig. 293 (as Peridinium crassipes); Dodge 1985: 48; Steidinger & Tangen 1997: 538, Pl. 53; Okolodkov 2005: 286, Fig. 5; Okolodkov 2008: 120, Pl. 12, Figs. 1–3; Krakhmalny 2011: 194, Table 79, 1–7. Basionym: Peridinium crassipes Kofoid 1907. Zool. Anz. 32: 309, pl. XXXI, Figs. 46–47. Description: Cells rhomboid or pentagonal, slightly or noticeably dorsoventrally compressed. The epitheca conical with concave lateral sides. The epithecal plate pattern comprises seven precingular plates (7ʹʹ), four apical plates (4ʹ), three anterior intercalary plates (3a), 1ʹ and 2a plates of “meta”–”quadra” type. Thecal plates reticulate. The cingulum median, descending, deep, bordered. The sulcus broad, deep, with developed left sulcal list. The hypotheca with concave sides and a notch near the antapex. Antapical horns close to each other and bear small spines at their ends. Dimensions: 84.2–90.0 µm long and 72.9–90.0 µm wide. Distribution: Coastal, even forms blooms in warm water estuaries. Temperate to tropical waters of seas and oceans; cosmopolitan (Steidinger & Tangen 1997). Data on the distribution of P. crassipes are given from the GBIF. org (2022) (Fig. 83).

Published as part of Krakhmalnyi, Aleksandr F., Krakhmalnyi, Maxim A., Terenko, Galyna V. & Goncharenko, Igor V., 2023, Dominant Species Of The Genus Protoperidinium Bergh (Peridiniales: Protoperidiniaceae) In The Black Sea, pp. 427-448 in Zootaxa 5339 (5) on page 434, DOI: 10.11646/zootaxa.5339.5.2, http://zenodo.org/record/8309419