Solution:

Calyx is a term used in animal anatomy for some cuplike areas or structures.

Entoprocta, whose name means “anus inside”, is a phylum of mostly sessile aquatic animals, ranging from 0.1 to 7 millimetres (0.004 to 0.3 in) long. Mature individuals are goblet-shaped, on relatively long stalks. They have a “crown” of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and both the mouth and anus lie inside the “crown”. The superficially similar Bryozoa (Ectoprocta) have the anus outside a “crown” of hollow tentacles. Most families of entoprocts are colonial, and all but 2 of the 150 species are marine. A few solitary species can move slowly.