Yoldia

a genus of marine bivalve mollusks. The shell is 1–4 cm long; its hinge has numerous teeth. There are approximately 20 species of Yoldia; they inhabit soft ground in ocean floors as deep as 200 m. There are eight species in the far eastern seas of the Soviet Union and one, Yoldia hyperborea, in the northern seas. The Yoldian Sea was named for the mollusk. Mollusks now classified in the genera Portlandia and Yoldiella used to be included in Yoldia.