1. Trivia arctica with mantle fully expanded. Dark marks near the yellow edges of the mantle should not be confused with the dark marks found on the dorsum of the shell of T. monacha.
2. Trivia arctica with mantle fully expanded. Dark marks near the yellow edges of the mantle should not be confused with the dark marks found on the dorsum of the shell of T. monacha.

Trivia arctica with mantle fully expanded. Dark marks near the yellow edges of the mantle should not be confused with the dark marks found on the dorsum of the shell of T. monacha.