Sculptured Top Shell
Calliostoma euglyptum A. Adams, 1855
The Sculptured Top Snail is shaped like an old-fashioned toy spinning top. It is about an inch tall and about an inch wide at the base. The angle of the spire is approximately 70 degrees. The rather sturdy snail shell has six whorls, the sides of which are slightly concave. Each whorl is decorated with beaded cords — six strong spiral cords of beads; and six alternate, fine, weakly-beaded threads on each whorl. (A whorl is one complete turn about the axis of a gastropod shell.) Calliostoma euglyptum has a transversely oval aperture. The somewhat similar-looking Jujube Top Shell has a more squarish opening, and more whorls. (Note: Worn beach shells will, of course, have less detailed sculpture, some of the tiny beads having been worn down. Also, beach shells may be faded.)
There are about 55 genera worldwide in the Top Shell family. All of them have a pearly interior, and the mollusk has a corneous (“horny”) operculum (the “door” of the aperture).
Top Shell snails graze on seaweed, vegetable detrius, and attached epibenthic organisms, including sponges.
The Sculptured Top Shell lives in shallow water, anywhere from the low-tide mark to water a depth of 180 feet. The shell might be found on beaches from North Carolina to Texas and Mexico.