marginalia vs scholium

marginalia and scholium both are nouns.

Word	Noun	Adjective	Verb	Adverb
marginalia	Yes	No	No	No
scholium	Yes	No	No	No

As nouns, scholium is a hyponym of marginalia; that is, scholium is a word with a more specific, narrower meaning than marginalia:

marginalia: notes written in the margin
scholium: a marginal note written by a scholiast (a commentator on ancient or classical literature)

Other hyponyms of marginalia include scholia.

marginalia (noun)	scholium (noun)
notes written in the margin	a marginal note written by a scholiast (a commentator on ancient or classical literature)