Drupes are small shells in shallow water. They have spines that can be pointed. the tops are usually very worn or covered in growth. Kauai 2013
This drupe is more worm with a lot of growth on it. Kauai 2004
Mulberry Drupe (Drupa morum) ムラサキイガレイシ size 3cm
A Mulberry Drupe. Kauai 2017
Pink Mouth Drupe (Ricinella rubusidaeus) アカイガレイシ – Strawberry Drupe – size 5cm
A Pink Mouth Drupe. Kauai 2022