They are called a sand collar and are made by Moon Snails. The eggs are molded by the shell curvature as the eggs are cemented with sand. The small eggs are in the central jelly area, covered by both sides with sand. Here in Southeast Alaska the snails use the available sand and are different color according to the color of that particular beach. Each species has its own characteristic color shape. -----Original Message----- From: Conchologists of America List Sent: Wednesday, June 10, 1998 12:28 PM To: ScottW; [log in to unmask] Subject: Sharks nest Hi shellers, I am looking for the "parent" of what we used to call a "sharks nest" found around Newport Beach bays, in calm ,shallow water. It is a collar of sand cemented togeather with some sort of mucus, with a hole in the middle. As kids, we used to think sand sharks made them for their eggs. But I have heard that the moon snail really makes them for their eggs. Does anyone know about this curios little nest? Thanks ,Leslie