Crinoids. A feather star is a habitat before it is an animal, and this group is short because the interest is in what is living in the arms.
A single feather star can hold a squat lobster, a shrimp and a clingfish, each coloured to match the arms it is sitting in. They are found by searching the animal rather than by seeing them, which is why a guide will spend a minute on a crinoid that looks empty.
Feather stars move. They walk on the cirri under the disc and some swim by beating the arms, and they shed arms readily, so an animal with arms of different lengths is normal rather than damaged.
Every one has a page. They are shown as a list rather than as pictures because nothing has been photographed or logged for them yet, and a species with nothing behind it should not sit in front of one that has.
How many of the 2 carry a record at each destination. A species usually carries several, so these do not add up to 2.
All 1316 species in one index, with filters for destination, rarity and hazard.