The Scorpion Shells Spider Shells

THE SCORPION SHELLS. SPIDER SHELLS Genus PTEROCERA, Lam.

Shell

spiral, oval, heavy, the outer lip prolonged into long finger-like processes. Animal like Strombus. Ten species.

Our American coasts have no representatives of this striking group. They are sociable, shore-loving mollusks, closely allied to Strombus. Where our genus exaggerates the outer lip into an unnecessary wing, these species use an equal amount of material in the long, curved fingers that make the mollusks look like great spiders or scorpions, travelling upon six or eight legs. The young have plain-lipped shells until quite well grown. Then the points

grow out as hollow canals containing filaments from the mantle margin. Ultimately they become solid. The surface bears strong knobs and ridges, and the smooth, polished aperture has a pink or orange lining. Tropical seas of the eastern hemisphere.

P.

bryonia, Chemn., from the Society Islands, is the largest species. The description above just fits it. The specimens approach a foot in length. Ponderous and coarse outside, the wide aperture reveals an expanse of fawn-coloured enamel tinged with pink that is truly beautiful.