Eunotia marginepunctata J.C.Taylor & Cocquyt, 2025

Eunotia marginepunctata J.C.Taylor & Cocquyt sp. nov. (LM: Figs 55–81 View FIGURES 55–81 ; SEM; Figs 82–85)

Description LM: — Frustule in girdle view broadly rectangular, striae present on valve mantle only, 12–14 in 10 μm. Ventral valve margins straight, convex dorsal margins. Valve poles not, to weakly protracted, rounded. Length 8.5–19.0 μm, breadth 3.5–5.0 μm. Terminal nodules close to the poles. Terminal raphe fissures short to very short on the valve face. Striae absent from valve face. Large areolae present on dorsal valve margins, 12–14 in 10 μm, smaller more densely spaced areolae on the ventral margin, 19 in 10 μm.

SEM: — Externally the terminal fissures extend onto the valve face and end in a slightly reflexed spathulate groove (Fig. 82). Internally the raphe fissures terminate in small raised helictoglossae (Figs 84, 85). Striae absent from the valve face, present on the dorsal and ( Figs 75–79 View FIGURES 55–81 ) and ventral valve mantle ( Figs 80, 81 View FIGURES 55–81 , 83), 12–16 in 10 µm, of irregular length and not reaching the edge of the valve mantle on the dorsal mantle. Rarely an isolated areola is present on the valve face near the terminal raphe fissure (Figs 84, 85, arrow). Rimoportulae not observed. Areolae at the valve margin, sometimes occluded by silica (Fig. 82), visible internally (Fig. 85). Small copula open near the pole (Fig. 82, arrow) and a broader girdle band with one row of round areolae, 28 in 10 µm (Fig. 83), sporadic an isolated areola present on this band.

Type:— DEMOCRATIC REPUBLIC OF THE CONGO. Tshopo Province : Moni River , just downstream from the campsite in the tropical rain forest, sand from the stream bed, 0°50’47.29”N and 24°32’36.63”E, CCA 4386 View Materials , Andreas Popelier , 18 Jul. 2017, (holotype BR! 4846, Meise Botanic Garden, Belgium; the valve representing the holotype is here illustrated in Fig. 60 View FIGURES 55–81 ; isotype SANDC! 24-538, South African National Diatom Collection, South Africa) GoogleMaps .

Registration:— http.//phyocbank.org/105518

Etymology:— We name this new Eunotia species based on the presence of the rows of distinct marginal areolae visible in LM and SEM.

Ecology and distribution:— The species was found in a stream with sandy substrate (Moni River). This taxon has not been observed from any other locality to date. No measurements of pH, conductivity or nitrate content were taken during the sampling.