Gomphoneis gracilis Kociolek, Kulikovskiy & Solak, 2013

Kociolek, John P., Kulikovskiy, Maxim S. & Solak, Cüneyt N., 2013, The diatom genus Gomphoneis Cleve (Bacillariophyceae) from Lake Baikal, Russia, Phytotaxa 154 (1), pp. 1-37 : 11-13

Gomphoneis gracilis Kociolek, Kulikovskiy & Solak , sp. nov. ( Figs 132–143 )

Valves linear-lanceolate clavate, with headpole slightly protracted, rounded, footpole rounded. Length 25–46 µm, breadth 4.5–7.5 µm. Axial area narrow, expanded at center to form a rounded to irregular rectangularshaped central area bordered by 2–5 shortened striae more coarsely separated from other striae. Central area contains 4 isolated stigmoids. Central area not expanded to the margin. Raphe lateral, straight, with external proximal raphe ends distinctly dilated. External distal raphe ends extend nearly straight onto the valve mantle. Striae costate, radiate about the center of the valve, to the footpole and towards the headpole, before becoming parallel at the apex. Striae 10–12/ 10 µm. Apical pore field distinct, composed of defined rows of porelli. Septa and pseudosepta distinct, especially at the footpole.

Type:— RUSSIA: Lake Baikal , White stone cape, on stone, N52 o 35.694, E107 o 17.141, 16.07.2011, leg. M. Kulikovskiy ( IBIW slide no. 18575m, holotype designated here (= Fig. 142 ); COLO slide no. 18575p, SZCZ slide no. 18575°, isotypes) .

Observations:— The unique outline of this species clearly differentiates it from other species in Lake Baikal.

Figures

PLATE 6: LM. Figs 120–127: Gomphoneis tumidoides sp. nov. Fig. 120 is of the holotype. Figs 128–131: G. rotundata sp. nov. Fig. 129 is of the holotype. Figs 132–143: G. gracilis sp. nov. Fig. 142 is of the holotype. Figs. 144–152: G. sp. cf. witkowskii. Figs 153– 158: G. lange-bertalotii sp. nov. Fig. 155 is of the holotype. Figs 159–168: G. witkowskii sp. nov. Fig. 168 is of the holotype. Scale bar = 10 µm for all figures.