spirilla vs true bacteria

spirilla and true bacteria both are nouns.

Word	Noun	Adjective	Verb	Adverb
spirilla	Yes	No	No	No
true bacteria	Yes	No	No	No

As nouns, true bacteria is a hypernym of spirilla; that is, true bacteria is a word with a broader meaning than spirilla:

spirilla: any flagellated aerobic bacteria having a spirally twisted rodlike form
true bacteria: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of spirilla include eubacteria, eubacterium.

spirilla (noun)	true bacteria (noun)
any flagellated aerobic bacteria having a spirally twisted rodlike form	a large group of bacteria having rigid cell walls; motile types have flagella