みぞかいじゃなかったです
溝貝じゃなかったです
mizokaijanakattadesu

Noun
Desu Copula

The polite, past negative form of どぶがい

1. Wasn't a groove shell.; Wasn't a scallop.

Past/Perfective
Negative
Polite
Casual Register
Usually Written in Kana