Cytheridella Daday 1905

GenusCytheridellaDaday, 1905 Onychocythere Tressler, 1939 (fide Pinto and Sanguinetti 1962). Syn. Type species. Cytheridella ilosvayi Daday, 1905. Syn.: Metacypris ometepensis Swain & Gilby, 1964 (fide Purper 1974; Martens and Behen 1994). Syn.: Onychocythere alosa Tressler, 1939 (fide Purper 1974; Cohuo et al. 2017). Syn.: Gomphocythere argentinensis Ferguson, 1967 (fide Karanovic 2009). Syn.: Cytheridella boldii Purper, 1974 (fide Danielopol et al. 2018). Diagnosis (partly derived from the extensive analysis of Danielopol et al. 2023). Cp largely sexually dimorphic. Males: CpV and CpD laterally rather flattened, with greatest width slightly behind the middle, both anterior and posterior sides pointed. Females: CpD and CpV with highly developed brood chamber, occupying 2 / 3 of the posterior part of the Cp, posterior margin almost straight, anterior margin pointed. In both sexes with well-developed lateral sulci and external valve surfaces heavily ornamented, with pits, rimmed pores with setae, and, especially anteriorly and posteriorly, with long and stiff setae and pores on conical elevations with setae (Porenwarzen). In inner views, both valves with well-developed anterior and posterior selvages, largely inwardly displaced; anterior calcified inner lamella of both valves set with two connected rows of long and fine cuticular filaments (setulae). Hinge adont. Central Muscle Scars consisting of a vertical row of four scars. A 1 with second segment bearing a long seta on the proximo-ventral side; penultimate segment fully or partly fused (segments 4 + 5); one of dorso-apical setae on this segment shaped as a trident. A 2 with three distal claws. T 1 and T 2 with segment En 4 fused with end claw. T 3 a reflexed “ cleaning limb ”, with segment 4 not fused with end claw, seta h 3 a spine. In females, with elongated CR (“ organ fourchu ”), with bifurcated tip. Hp with DL hinging on basal part, copulatory process coiled, short or (very) long. In males, CR simple but robust setae. Other (African) species. C. damasi Klie, 1944 (Congo, syn.: C. chariessa Rome, 1977 (Congo, in Rome and De Deckker 1977, fide Karanovic 2009)); Cytheridella monodi Klie, 1936 (Cameroon) Cytheridella tepida Victor, 1987 (Nigeria). Remark. Cytheridella americana (Furtos, 1936) Danielopol (1981 in Colin and Danielopol 1980) from Yucatan (Mexico) is here considered an uncertain species (see below).