Two Large Marine Specimen Shells comprising a King Helmet Shell and a Giant Clam Valve

This lot features two substantial marine specimen shells. The first is a single valve from a giant clam, of the Tridacna species, notable for its heavy-walled construction and deep radial ribs with strongly undulating, fluted margins. The exterior has a weathered off-white appearance with some natural calcification, while the interior is a smooth, polished white, clearly showing the muscle scar and hinge area. The second specimen is a King Helmet shell (Cassis tuberosa), a large marine gastropod with a prominent spire and a row of blunt spines at the shoulder. It features a wide, flattened parietal shield and a long, narrow aperture lined with thick teeth. A distinguishing feature of this species is the dark chocolate-brown to blackish pigmentation visible between the teeth. Both specimens are unmounted and free-standing. Please note that certain species of Tridacna are protected under CITES Appendix II regulations, which may restrict international trade and transport.