Phylum: Charophyta   Family: Desmidiaceae

Hyalotheca dissiliens J. Ralfs 1848

First described and illustrated by Ralfs (1848: 51, pl. 1: 1). Cells broader than long with a slight median constriction. Circular in apical, view. Filaments usually found with a thick mucilaginous sheath. Zygospore globose or subglobose.
Cell dimensions: L: 15-25 µm; B: 15-30 µm; L/B: 0.5-0.8. Zygospore: 20 x 30 µm.
Very common in mesotrophic waters, which are slightly acidic.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
Ralfs, J. (1848) The British Desmidieae.
West, W., West, G.S. & Carter, N. (1923) A Monograph of the British Desmidiaceae, Volume 5.