Description: Characterised by relatively large valves for a diatom in the microcephala -complex, lanceolate to broadly lanceolate in outline with convex margins and rostrate to subcapitate apices. Length 13.6–31.6 μm; width 3.0– 4.5 μm; maximum L:W ratio 8.3. Mostly comparable to the type description but populations in Irish lakes also have distinctly capitate rounded apices (Figs 492–494, 505, 509). Larger valves and initial cells may have non-protracted narrowly rounded ends. Striae are parallel or weakly radiate at centre, becoming increasingly radiate towards the poles. Stria density 25–30 dorsally and 24–29 ventrally in 10 μm. Stria density in Irish populations exceed that reported for type material and valves have a higher maximum L:W ratio. Axial area narrow and central area absent, rarely with a single slightly shortened stria at valve centre. Ultrastructural characters are equivalent to that given with the original species description.

Ecology: E. neerlandica is widespread in peatland catchments in the West of Ireland, occurring in 26 lakes and reaching a maximum relative abundance of 54%. Its ecology is equivalent to that reported by Van de Vijver et al. (2012) and is found in low to moderate alkalinity, near-neutral humic lakes. It is also found in a number of samples from Cronaniv Burn (max. 9.5%), a river in a near-pristine peatland catchment overlying siliceous geology in Co. Donegal and less frequently in the Bundorragha River, a lake outflow in Co. Mayo. Although found in near-pristine reference lakes, it has a maximum abundance at mesotrophic condition, suggesting a sensitivity value of S=2 for lake ecological assessment (Fig. 532).