Pawsonia saxicola has a solid, cylindrical body and can grow to a length of 150 mm (6 in).

The mouth is at the anterior end and is surrounded by a circle of ten, black and white, mottled, branching, tentacles used for feeding, up to 100 mm (4 in) long.

Both live in crevices with their dark-coloured tentacles projecting; P. saxicola is white, but may darken somewhat when exposed to light, while Aslia lefevrei is brown.

[2] Pawsonia saxicola is a suspension feeder, consuming diatoms and single-cell algae and also zooplankton, such as copepods, ostracods, protozoans, nematodes, jellyfish and larvae, as well as drifting organic particles.

The food is gathered by the feeding tentacles which each in turn shrinks and bends and is inserted into the mouth; the two ventral tentacles are short and forked, and are used at the mouth to push particles inside.