The term "Subclass Euryalida" refers to a group of marine animals that belong to the class Asteroidea, or more commonly known as starfish. Some synonyms that can be used to refer to Euryalida include basket stars, writhing stars, and brittle basket stars. These unique creatures have thin and elongated arms that branch into numerous smaller arms, giving them a basket-like appearance. They can be found in oceans worldwide, primarily dwelling in deeper waters. Euryalida are known for their intricate feeding mechanism, where they use long and sticky tube feet to capture small animals floating in the water. While they may not be as well-known as some other marine creatures, Euryalida are fascinating to study and observe.