subclass Teleostei vs Teleostei

subclass Teleostei and Teleostei both are nouns.

Word	Noun	Adjective	Verb	Adverb
subclass Teleostei	Yes	No	No	No
Teleostei	Yes	No	No	No

As nouns, subclass Teleostei and Teleostei are synonyms defined as:

subclass Teleostei and Teleostei: large diverse group of bony fishes; includes most living species

subclass Teleostei (noun)	Teleostei (noun)
large diverse group of bony fishes; includes most living species	large diverse group of bony fishes; includes most living species