I'm doing an overhaul of this phylum

I want overhaul these phylum too after learning more about earth arthropods!

The beant is a small soft bodied animal with 4 pairs of legs and 5 eyes. They are named for their rounded body shape. They have hydro-static skeleton which helps them efficiently move and forage along the sea floor.

The corr is a superficially starfish-like, soft bodied animal. They have spend their time near the sea floor using 5 arms with a sticky pad at the end of each to catch food from the current and bring it to their mouth. They have 5 simple eyes in the junction between the arms, which can detect light.

 A colonial organism that feeds on the debris on the sea floor that can reach massive sizes. There are two main types, one with powerful stinging tentacles and another with weak stings. Those with powerful stings sometimes catch small animals to supplement their diet. The weak sting variety mostly use uses their stings to keep other animals from munching on them. They appear fairly early on in the timeline and do not go extinct until the oceans dried up.

(Fun Fact: This organism is based on cryptid stories from deep sea divers on Earth! Some of these stories are a bit ridiculous, featuring miles of a mat of wriggling tentacles with stinging tendrils powerful enough to paralyze orcas with one touch.)