Figs 25–57 in Four new monoraphid diatom species (Bacillariophyta, Achnanthaceae) from the Maritime Antarctic Region

Figs 25–57. Planothidium wetzelectorianum Kopalová, Zidarova & Van de Vijver sp. nov. Light and scanning electron micrographs of the type population in Monolith Lake (James Ross Island). 25. LM view of a girdle view. 26–38. LM views of raphe valves. 39–52. LM views of rapheless valves. 53. SEM external view of an entire raphe valve. 54. SEM external detail of the areolae. 55. SEM internal view of the raphe and the striae. Note the hymenes on the areolae. 56. SEM external view of an entire rapheless valve. 57. SEM internal view of an entire rapheless valve. Scale bars represent 10 µm for Figs 25–52, 1 µm for Figs 53–57.