Pieces removed from various parts of the shell were replaced by the mantle. In adult shells these repairs were irregular in form and atypical in growth, i.e., they lacked the cuticle and complex organization of the normal shell. In immature individuals injuries to the aperture of the shell were repaired by typical growth in which perfect shell having hypostracum, ostracum, and cuticle was laid down, but a scar remained. At maturity the mantle loses the ability to make cuticle and ostracum and makes only inner layers. The methods of shell repair in this snail agree with descriptions of those in various European fresh-water, marine, and land snails in being typical or atypical.