coccobacillus vs eubacteria

coccobacillus and eubacteria both are nouns.

Word	Noun	Adjective	Verb	Adverb
coccobacillus	Yes	No	No	No
eubacteria	Yes	No	No	No

As nouns, eubacteria is a hypernym of coccobacillus; that is, eubacteria is a word with a broader meaning than coccobacillus:

coccobacillus: a bacterial cell intermediate in morphology between a coccus and a bacillus; a very short bacillus
eubacteria: a large group of bacteria having rigid cell walls; motile types have flagella

Other hypernyms of coccobacillus include eubacterium, true bacteria.

coccobacillus (noun)	eubacteria (noun)
a bacterial cell intermediate in morphology between a coccus and a bacillus; a very short bacillus	a large group of bacteria having rigid cell walls; motile types have flagella