As a proper noun coral

is .

As a noun anthozoan is

(marine biology) a marine invertebrate of the class anthozoa, such as a sea anemone or coral.

Anthozoic is a related term of anthozoan.

As an adjective anthozoic

is of or pertaining to the anthozoa.

As a noun anthozoan is

(marine biology) a marine invertebrate of the class anthozoa, such as a sea anemone or coral.

As nouns the difference between polyp and corallite

is that polyp is an abnormal growth protruding from a mucous membrane while corallite is the hard outer cup of a coral polyp.

As nouns the difference between diatom and theca

is that diatom is a group of minute unicellular algae having a siliceous covering of great delicacy, now categorized as class class: Diatomophyceae or division Bacillariophyta, formerly all included in the order order: Diatomaceae, now obsolete while theca is any external case or sheath.

As nouns the difference between dinoflagellate and theca

is that dinoflagellate is any of many marine protozoa, of the phylum dinoflagellata, that have two flagella while theca is (biology) any external case or sheath.

As an adjective calcareous

is resembling or containing calcium carbonate or limestone; chalky.

As a noun theca is

(biology) any external case or sheath.

In coral science|lang=en terms the difference between corallite and theca

is that corallite is (coral science) the hard outer cup of a coral polyp while theca is (coral science) the calcareous wall of a corallite, the exoskeleton of a coral polyp.

As nouns the difference between corallite and theca

is that corallite is (coral science) the hard outer cup of a coral polyp while theca is (biology) any external case or sheath.

As nouns the difference between polyp and theca

is that polyp is polyp while theca is (biology) any external case or sheath.

Theca is a related term of thecium.

As nouns the difference between thecium and theca

is that thecium is the hymenium while theca is any external case or sheath.

In biology|lang=en terms the difference between theca and thecate

is that theca is (biology) any external case or sheath while thecate is (biology) having a theca, or outer sheath.

As a noun theca

is (biology) any external case or sheath.

As an adjective thecate is

(biology) having a theca, or outer sheath.