The corrosion resin-casts and the tissue preparations of the digestive diverticula of the Half-crenated ark, Scapharca kagoshimensis were observed. The resin-casts were made of the prepolymerization methyl methacrylate (MercoxCL-２R) containing 10 % Mercox MA. The tissue preparations were stained with Azan. The digestive diverticula (D) surrounded the oesophagus and the pyloric part of the stomach. In the middle of the stomach 13 or 14 ducts of the digestive diverticula (DD) showing orifice in structure started in a line in the middle of the stomach. The lumen of the duct (DD) was covered with brush border and cilia. The structure was the same in all parts of the duct (DD) even at the branching tips. The tubules of the digestive diverticula (T) branched after arising from the duct (DD).