phragmacone vs phragmocone

phragmacone and phragmocone both are nouns.

Word	Noun	Adjective	Verb	Adverb
phragmacone	Yes	No	No	No
phragmocone	Yes	No	No	No

As nouns, phragmacone and phragmocone are synonyms defined as:

phragmacone and phragmocone: the thin conical chambered internal shell (either straight or curved) of a belemnite

phragmacone (noun)	phragmocone (noun)
the thin conical chambered internal shell (either straight or curved) of a belemnite	the thin conical chambered internal shell (either straight or curved) of a belemnite