class Hydrozoa vs hydrozoan

class Hydrozoa and hydrozoan both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Hydrozoa	Yes	No	No	No
hydrozoan	Yes	No	No	No

class Hydrozoa (noun)	hydrozoan (noun)
coelenterates typically having alternation of generations; hydroid phase is usually colonial giving rise to the medusoid phase by budding: hydras and jellyfishes	colonial coelenterates having the polyp phase dominant