Phylum: Charophyta   Family: Desmidiaceae

Hyalotheca tatrica (M. Raciborski) P.F.M. Coesel & K.J. Meesters 2023

First described and illustrated by Raciborski (1885: 64, pl. 14: 5) as Hyalotheca dissiliens var. tatrica. Very recently, Coesel & Meesters (2023: 258) raised it to species level. It's rarely recorded and possibly restricted to Arctic-alpine regions. West, West & Carter (1923: 234) only recorded it from Hawkshead, Lancashire.
Cell dimensions: L: 16-20 µm; B: 14-18 µm; L/B: 1.00-1.20.
Found in mesotrophic waters, which are slightly acidic, but rarely recorded.

References: 
Coesel, P.F.M. & Meesters, K.J. (2023 second edition) Desmids of the Lowlands.
Raciborski, M. (1885) Opisy nowych desmidyjów polskich. De nonnullis Desmidiaceis novis vel minus cognitis quae in Polonia inventae sunt.
West, W., West, G.S. & Carter, N. (1923) A Monograph of the British Desmidiaceae, Volume 5.