Below you can find the A clam shell has 3 layers: the horny outer layer the prismatic layer & one described as this Jeopardy Words Answer. The answer to A clam shell has 3 layers: the horny outer layer the prismatic layer & one described as this has 6 letters. This clue belongs to the Biology category and is part of Jeopardy Word Level 927. If you scroll near the bottom you will find other clues and answers part of level 927