Redefinition of the Dinoflagellate Genus Alexandrium Based on Centrodinium: Reinstatement of Gessnerium and Protogonyaulax, and Episemicolon gen. nov. (Gonyaulacales, Dinophyceae)

Figure 3

Light (a–s) and scanning electron (t–z) micrographs of Centrodinium eminens. (a) Several individuals. (b) Left face. (c) Right epitheca. (d) Left-ventral view. The insets show the sulcus. (e) Dissociated plates of the apical horn. (f–g). Ventral views. The inset shows the sulcus. (h) Dissociated epitheca and hypotheca. (i–m) Several views of the same epitheca. (o, q) Dissociated posterior lateral sulcal plates. (p) Anterior sulcal. (r) Posterior sulcal and first antapical plate. The arrowhead points a filiform extension. (s) Antapical horn. (t) Left face. (u–v) Right face. (w–z) Apex. 1′–4′ = apical plates; 1′′–6′′ = precingular plates; 1′′′–5′′′ = postcingular plates; 1′′′′–2′′′′ = antapical plates; C1–C6 = cingular plates; c.p. = closing, cover platelet or canopy; mp = marginal pores surrounding the apical pore plate; Po = apical pore plate; S.a. = anterior sulcal plate; s.a.p. = pore of the anterior sulcal plate; S.d.a. = right (dexter) anterior lateral sulcal; S.d.p. = right posterior lateral sulcal; S.m.a. = anterior median sulcal; S.m.p. = posterior median sulcal; S.p. = posterior sulcal; S.s.a. = left (sinister) anterior lateral sulcal; S.s.p. = left posterior lateral sulcal plate; Scale bar (a–v) = 20 μm, (w–z) = 2 μm.