👉 The term "Opalinopsidae" refers to a group of marine gastropod mollusks that belong to the family Opalinopidae, which are commonly known as opal worms or opal crabs. These mollusks have a wide range of cephalopods and are characterized by their unique shell-like structure, which is composed of two fused ocelli (the main chambers) and a series of small spiral structures called cilia. The genus name "Op