Genus Tugonia Gray, 1842

Tugonia Gray, 1842: 44, 78; Gray, 1847: 190.

Tugonia Récluz, 1846: 168, 174 (fide Lamy, 1927).

Diagnosis. Shell size medium to small, globose, posterior area small and set off by constriction or demarcated by ridge; sculpture of commarginal growth lines or also with radial ribs; chondrophores subequal, slightly larger in left valve; pallial sinus shallow.

Type species. Mya anatina Gmelin, 1791 (subsequent designation by Gray, 1847).