Phylum: Charophyta Family: Desmidiaceae
Cosmarium sp. (13)
Cells small to medium sized, marginally longer than broad, subcircular in outline, deeply constricted; sinus with a dilated apex and closed for half its length then slightly undulate. Semicells a slightly broadened semicircle, basal angles rounded with yellowish thickening, also a little protracted. Apex broadly rounded; cell wall in face-view faintly undulate, caused by the mucus pores. Apical view rhomboid with side thickening, lateral view circular. Chloroplast axile with two central pyrenoid. Zygospore unknown.
Cell dimensions: L. 33.1-34.7 µm; B. 31-33 µm; Is. 11.2-12.7 µm; Th. 17.8-18.5µm; L./B. 1.05-1.08.
This taxon is currently being written up as an undescribed species.