Phylum: Chlorophyta   Family: Scenedesmaceae

Coelastrum microporum C. Nägeli 1855

First described by (Nägeli 1855: 70) but not illustrated. One of the smaller members of the genus with smooth, rounded surfaces.
Coenobia broadly spherical, usually 8, 16, & 32 celled. Cell diameters: 6-12 µm.
Widely reported across the British Isles with May and June the best months to find it.

References: 
John, D.M., Whitton, B.A. & Brook, A.J. (2011 second edition). The Freshwater Algal Flora of the British Isles.
Nägeli, C. in Braun, A. (1855). Algarum unicellularium genera nova et minus cognita praemissis observationibus de algis unicellularibus in genere.