Apple Murex Sea Shells - Phyllonotus pomum. This thick and solid sea shell features a slightly elongated shape with convex whorles. The sea shell consists of alternating thick and thin ribs which are nodular or spiny at the intersections. Common in depths of 1 to 20 meters from the S. E. United States to Brazil. Measures approx 2 1/4"- 2 3/4". Also great for Hermit Crabs. The hermit crab opening measures approx. 1"- 1 1/2" in diameter.