In Gen 3, eggs always have the word Egg (in Japanese) as the species name. The language field has a special value that localizes it ingame.
IIRC, PKHex thinks that special value is Japanese.
Updated.
Won't be any further updates for a bit as the rest will take quite a bit of farming.
Missing:
809 - Melmetal
Missing (Pokemon Go):
Raichu-Alola
Sandshrew-Alola
Sandslash-Alola
Vulpix-Alola
Ninetales-Alola
Diglett-Alola
Dugtrio-Alola
Meowth-Alola
Persian-Alola
Machamp
Golem-Alola
Grimer-Alola
Muk-Alola
Exeggutor-Alola
Marowak-Alola
Hitmonlee
Ditto
Articuno
Zapdos
Moltres
Mewtwo
Mew
Melmetal