homotypic synonym, validly published under the ICNP
Streptococcusadjacens is the correct name if this species is regarded as a separate species within a separate genus Streptococcus.
It is true that this practice has become rare . However, a such change should be applied to many nomenclatural names (examples: Janibacter, Janthinobacterium, …) that is not desirable, because an essential point in nomenclature is the stability of names [Principle 1 of the Bacteriological Code (1990 revision)].
The Latin i, when used as a consonant, is often printed as j in earlier dictionaries and classical texts .Publication:
Gaffiot F. Dictionnaire latin français. Hachette, Paris, 1934.
The spelling of the specific epithet is adjacens in the nomenclatural name Streptococcus adjacens and adiacens in the nomenclatural name Abiotrophia adiacens. Y. Kawamura et al. used adiacens because the IJSB editor recommended to use i instead of j . — Frederiksen W. Personal communication, unspecified date.