Gloeocapsa nigrescens Nägeli in Rabenhorst (1865: 40) (Fig. 8I).

Colonies round to elongated, 14.31–42.19 (66.66) µm wide.Without sub-colonies. Sheath firm, thin, slightly granulated, blackish. Cells densely to sparsely arranged, spherical, 2.55–7.93 µm wide. Individual envelopes firm, conspicuous, slightly granulated, blackish. Cell content homogenous to granulated, blue-green. Without cell in resisting stage.

Habitat:— Concrete.

Studied material:— PEUFR55777