Calyculus and Optic cup

Calyculus noun - A small cup-shaped structure (as a taste bud or optic cup or cavity of a coral containing a polyp).

Optic cup and calyculus are semantically related. In some cases you can replace phrase "Optic cup" with "Calyculus", this terms are similar.

Optic cup noun - (embryology) a two-walled cuplike depression that develops into the pigmented and sensory layers of the retina.

Calyculus and optic cup are semantically related. You can use "Calyculus" instead a noun phrase "Optic cup".