Celleporella hyalina is a common encrusting bryozoan that forms small sub-circular patch-like colonies, up to 20 cm in diameter. Often colonies are aggregated in flat clumps. Young colonies appear glassy at first, later turning opaque and ivory-white. Autozooids are elongate and oblong, more or less sausage-shaped. They lie in contact with one another and are approximately 0.37 by 0.17 mm.
The precise geographic range of Celleporella hyalina is uncertain, since some records have almost certainly been derived from misidentified Haplopoma graniferum. Celleporella hyalina is known for certain from the Arctic, extending south along European coasts as far as the Bay of Biscay and along the Pacific coast of America to California, the parts of Mexico affected by cold water upwelling and Chile. It is also present on the eastern coast of Canada, Main and Massachusetts, but records from south of Cape Cod are likely to be incorrect. In Britain it has been recorded from the Menai Straits, Anglesey and North Wales.
The species is mainly found on algae and may reach great abundance on Laminaria sp., especially Laminaria saccharina, in sheltered waters. It is also occasionally found on stones and shells. The species ranges from the intertidal down to 55 m.
Since the L. saccharina fronds that this bryozoan species colonises show seasonal availability in the UK, C. hyalina completes its life cycle quickly, with colonies living for less than a year, typically around 4 months. This may be extended to 18 months or more on artificial substrates.