Phylum: Charophyta Family: Desmidiaceae
Cosmarium sp. (4)
Another mystery cell which I have shown to Frans Kouwets. The best I can do is quote him: "The photos show a nice bi-radiate smooth-walled desmid ornamented with a rather coarse pattern of cell wall pores and with a remarkable lateral wall thickening. Since the entire outline of the cells is in focus a central inflation apparently is absent. (In that case the cells would be in oblique view with either the left or right lateral side out of focus.) I have no idea about its identification; I think it’s a Cosmarium (related to C. contractum?) but it might be a bi-radiate form of a Staurastrum (related to S. orbiculare?), indeed."