おういとかけがいであれば
大糸掛貝であれば
ō itokakegaideareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of おおいとかけがい

1. If it is a large Ito-kake shell; If it were a large Ito-kake shell

Ba Conditional
Usually Written in Kana