Myxomycetes vs class Myxomycetes

Myxomycetes and class Myxomycetes both are nouns.

Word	Noun	Adjective	Verb	Adverb
Myxomycetes	Yes	No	No	No
class Myxomycetes	Yes	No	No	No

As nouns, Myxomycetes and class Myxomycetes are synonyms defined as:

Myxomycetes and class Myxomycetes: the class of true slime molds; essentially equivalent to the division Myxomycota

Myxomycetes (noun)	class Myxomycetes (noun)
the class of true slime molds; essentially equivalent to the division Myxomycota	the class of true slime molds; essentially equivalent to the division Myxomycota