These clams have two short siphons, each with a horny sheath. The shell is shaped like a rounded-cornered equilateral triangle and there is a slight gape at the posterior. Each valve bears two cardinal teeth with four lateral teeth on the right valve and two on the left. The foot is white and wedge-shaped. They mostly inhabit the neritic zone.[1]
Ecology
Trough shells burrow in sand or fine gravel and never in muddy substrates.[1]
^Kong, Lingfeng; Li, Qi; Qiu, Zhaoxing (2007). "Genetic and morphological differentiation in the clam Coelomactra antiquata (Bivalvia: Veneroida) along the coast of China". Journal of Experimental Marine Biology and Ecology. 343: 110–117. doi:10.1016/j.jembe.2006.12.003.
^Coan, E. V.; Valentich-Scott, P. (2012). Bivalve seashells of tropical West America. Marine bivalve mollusks from Baja California to northern Peru. pp. 2 vols, 1258 pp.