Phylactella labrosa is an encrusting bryozoan. Colonies form small circular or irregular patches; or frequently the colony diffuses in single or multiple linear series, branching irregularly and producing fans or patches intermittently. Autozooids are oval and convex, typically 0.4-0.56 by 0.3-0.4 mm.
Phylactella labrosa is a north-eastern Atlantic species. It occurs along the south and western coasts of the British Isles, on offshore shell gravels, from Sussex and Cornwall, northward to the Shetlands. The species is rarely reported and its precise geographical distribution is unknown.
The species is able to colonise hard substrates and is characteristic of small shell substrata. It occurs on the underside of valves of Venerupis, Tapes and other Veneracea, often in association with other encrusting bryozoans such as Neolagenipora collaris, Trypostega venusta, Escharina johnstoni, Puellina spp., and other cheilostomates with small ovicells.