Polymesoda is a genus of clams in the family Corbiculidae, or alternately, the Cyrenidae. Species include: \n* Polymesoda acuta \n* Polymesoda anomala \n* Polymesoda arctata \n* Polymesoda bengalensis \n* Polymesoda boliviana \n* Polymesoda caroliniana (Bosc, 1801) — Carolina marsh clam \n* Polymesoda exquisita \n* Polymesoda floridana \n* Polymesoda fontainei \n* Polymesoda inflata \n* Polymesoda maritima (Orbigny, 1842) — maritime marsh clam \n* Polymesoda meridionalis \n* Polymesoda mexicana \n* Polymesoda notabilis \n* Polymesoda obscura \n* Polymesoda ordinaria \n* Polymesoda powelli \n* Polymesoda proxima \n* Polymesoda radiata \n* Polymesoda tribunalis