New species of shore flies (Diptera: Ephydridae) from the Delmarva States are described, and taxonomic clarifications are made. The six new species are (type locality in parentheses): Discocerina delmarva (Virginia. Stafford: Aquia Harbour, Lions Park), Hydrochasma aquia (Virginia. Stafford: Aquia Harbour, Lions Park), Hydrochasma avanae (Utah. Grand: Swasey Beach (N Green River; shore of Green River; 1255 m), Hydrochasma garvinorum (Virginia. Rappahannock: Hazel River (NW Culpeper; 171 m)), Allotrichoma deonieri (Virginia. Spotsylvania: Rappahannock River), and Hydrellia toma (Virginia. Fairfax: Great Falls (Clay Pond)). The taxonomic changes are as follows: Psilopa obscuripes Loew is the correct name for “P. compta” of New World authors, nec Meigen; Discocerina parva Loew is confirmed as a junior synonym of Discocerina obscurella (Fallén), and the identification of the latter species is clarified with detailed illustrations and description of structures of the male terminalia.