Shell working. Mollusks were important food resources, but their shells may have been equally as important in prehistoric subsistence. Toolstone, such as chert, was not readily available along the coast, and shell provided a useful substitute. Coastal peoples were skilled and creative in shell technologies, utilizing a variety of mollusks in their work. The large shells of whelk and conch were used for both tools and ornaments. Unmodified, the heavy shells could be used as hammers; with several cuts, the inner columella became adzes and gouges for woodworking. Whelk and oyster shells, when perforated, became effective net weights for fishing. The straight edges of bivalves, such as sunray venus clams, could be used with little modification as knives and scrapers. Flat sections, or blanks, cut from various shells were made into arrowpoints as well as disc beads.