suborder Myxinoidei vs Myxinoidea

suborder Myxinoidei and Myxinoidea both are nouns.

Word	Noun	Adjective	Verb	Adverb
suborder Myxinoidei	Yes	No	No	No
Myxinoidea	Yes	No	No	No

As nouns, suborder Myxinoidei and Myxinoidea are synonyms defined as:

suborder Myxinoidei and Myxinoidea: hagfishes as distinguished from lampreys

Other synonyms of suborder Myxinoidei include Hyperotreta, Myxiniformes, Myxinoidei, suborder Hyperotreta, suborder Myxiniformes.

suborder Myxinoidei (noun)	Myxinoidea (noun)
hagfishes as distinguished from lampreys	hagfishes as distinguished from lampreys