Smittina bella is an encrusting bryozoan that forms thick spreading sheets, composed of a single layer of autozooids. Colonies often develop as rounded patches, normally greater than 25 mm in diameter. Autozooids are oval, hexagonal or irregular. They are 0.6-0.7 by 0.3-0.4 mm
Smittina bella was originally described from Shetland. It is known for certain from off Aberdeen and Norway. Its wider distribution remains unclear owing to taxonomic confusion with the sub-arctic Porella concinna var. belli and potentially other boreal-arctic smittinids.
The species is able to colonise stones in offshore habitats.