Phylum: Charophyta Family: Desmidiaceae
Cosmarium sp. (8)
Another mystery: I can't do better than to quote Frans Kouwets "The small crenate form with marked scrobiculus is unknown to me and I haven’t found matching forms in Prescott’s American flora. I don’t think it is closely related to C. blyttii. It would be interesting to study the cell wall ornamentation under SEM; it might very well be an undescribed species."