Phylum: Chlorophyta   Family: Chlorellaceaea

Geminella mutabilis  (L.A. de Brébisson) N. Wille 1909

First described and illustrated by Brébisson (1844: 26, pl. 1:1) as Hormospora mutabilis. It was later moved to its current genus by Wille (1909: 72).
Dimensions: cells: L: c.40 µm; B: 12-19 µm. Sheath: B: 38-45 µm.
Found in Sphagnum bogs, moorland pools and disused peat-cuttings. Distribution in the Outer Hebrides unclear but infrequently recorded.

References: 
Brébisson, L.A. de (1844). Description de deux nouveaux genres d'algues fluviatiles.
Wille, N. (1909). Conjugatae und Chlorophyceae. In: Die natürlichen Pflanzenfamilien ... Nachträge zum I.
Teil, Abteilung 2 über die Jahre 1890 bis 1910. (Engler, A. & Prantl, K. Eds)