Stenolaemata are a class of marine bryozoans with tubular zooids with strongly calcified walls. They are characterized by a lophophore which is protruded by the action of annular muscles. Most forms lack an operculum. The fossil Batostoma genus (member of order Trepostomatida) existed in monticular colonies. Stenolaemata were the predominant bryozoan group during the Paleozoic. Some grew as lacy or fan-like colonies that became important reef builders and in some regions form an abundant component of limestones. Their numbers were greatly reduced during the terminal Permian extinction event, but a single order, the Cyclostomatida, survives today.
In the Virtual Museum there are total 237 samples