Pleurocapsa sp.
Macrocolonies in form of black, more or less concentric spots on the concrete surface, partially going into the substrate (slightly boring morphotype). Complex life cycle of the microcolonies with different stages hard to recognize in the natural materials (isolation required for better identification). However, microcolonies occurs in the pseudofilamentous forms with rare pseudodichotomous branchings near the apices, from short to long, 14 - 45 µm long. Sometimes pseudofilaments aggregates in the upright fascicles, forming parallel rows, morphologically similar to Cyanodermatium spp., occasionally forms radiating colonies. Cells in the pseudofilaments disconnected physiologically, but densely packed, often with one row, but sometimes with two cells in the row, usually oval, quadratic, rarely elongated, longer than wide, slightly blue-green to olive-green, 3 – 6.5 X 3.8 – 6.96 µm, usually with granulated cytoplasm. Sheaths hard, yellowish-brown, robust in the apical parts of pseudofilaments, sometimes almost transparent, tightly attached to the cells (rarely slightly widened). Palmelloid stages frequently observed, supposedly, on the surface of concrete, since baeocytes deriving from them (and for the easy dispersion, baeocytes usually occurs on the surface of the substrate), with several Chroococcus-like cells enclosed into the mucilageous matrix, 3 – 4.5 µm in diameter. Coccoid stages also present (resting cells?) with robust intensely yellow sheaths, with different cells shapes, from rounded to irregular, 3 – 5.8 (6.3) µm in diameter. Baeocytes rare, derives from enlarged mother cells (6.7 – 9.2 µm in diameter) with blackish-violet sheaths, 1.5 – 2 µm in diameter (since sheaths of the mother cells has different color, shape and size it is possibly that this cells belongs to different species).
Taxonomic notes:
Pleurocapsa sp. is similar to Onkonema spp., but differs in terms of ecology and baeocyte production.
Pleurocapsa sp. is similar to Siphononema spp., but differs in terms of lacking frequent Chamaesiphon-like stages and also absent of massive multicellular pseudofilaments. 
Pleurocapsa sp. is similar to Hyella, but differs in terms of macrocolonies which only slightly boring substrate, also, pseudofilament aren’t so long and not divaricate, additionally vegetative cells are not having long gaps between each other’s.