Encyonopsis sp. 3

Kennedy, Bryan, Buckley, Yvonne & Allott, Norman, 2019, Taxonomy, ecology and analysis of type material of some small Encyonopsis with description of new species in Ireland, Phytotaxa 395 (2), pp. 89-128 : 113

Encyonopsis sp. 3 ( Figs 405–416 )

Description: Valves are moderately dorsiventral, lanceolate to elliptic-lanceolate. Clearly convex dorsal margin and slightly convex ventral margin. Apices are rounded nonprotracted or appearing only very slightly protracted with careful focusing. Length 9.9–13.5 μm; width 2.5–3.3 μm; maximum L:W ratio 4.5. Striae (26–30 in 10 μm) are weakly radiate and usually shortened both dorsally and ventrally at central area. Raphe filiform, clearly deflected dorsally at proximal and distal ends. Proximal endings slightly dilated and terminating in an inconspicuous pore. Distal raphe fissures are ventrally curved then acutely hooked towards ventral margin. Puncta are oval shaped and slightly larger in diameter towards axial area. This form may represent a size reduction of E. horticola but also has an affinity with E. perborealis and E. vandamii , although its morphology does not fit any of these taxa exactly.

Ecology: A rare form occurring in only 4 lakes and always at low relative abundance (1–6.5%). Environmental data from these lakes suggest an optimum at mesotrophic conditions.

Figures

FIGURES 405–416. Encyonopsis sp. 3 Figs 405–412. LM. Figs 405–412. Valves showing morphological range and size variation. Figs 413–416. SEM. Figs 413 & 415. External view. Figs 414 & 416. Internal view. Scale bar in Fig. 412 = 10 μm for all LM figures. Scale bar in all SEM micrographs = 2 μm.