Yes, these are the same Leydiers. I have six children born to Alphonse Leydier and Justine Mazellier: Marie Justine, Alphonse, Pauline, Lucie, Anaïs, and Marius. The elder daughters, Marie Justine and Pauline were already married at the time of their emmigration from France. Surprisingly, the family passed through Ellis Island before going to Northern Ontario.
If you descend from them, I would love to know how.I descend from Pauline Fabre who married Adolphe Fabre. Also, I have traced the Leydier genealogy back a couple more generations in France.