genus Geomys vs mammal genus

genus Geomys and mammal genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Geomys	Yes	No	No	No
mammal genus	Yes	No	No	No

As nouns, mammal genus is a hypernym of genus Geomys; that is, mammal genus is a word with a broader meaning than genus Geomys:

genus Geomys (noun)	mammal genus (noun)
type genus of the Geomyidae	a genus of mammals