Wikipedia
Cystoporata
Cystoporata is an extinct order of Paleozoic bryozoans. Their fossils are found from Ordovician to Permian strata.
All cystoporatan bryozoan genera (around 50 or so) have a "cystopore," a chamber-like supporting structure, separated from each other by transverse septa, situated between the characteristically elongated zooecias of each individual colony.