↑ Clark, Shattuck & Dall, The Miocene Deposits of Maryland, Maryland Geological Survey (1904), Pl. LII no. 1 as "Ecphora quadricostata".
↑ Ward & Gilinsky, 'Ecphora (Gastropoda: Muricidae) from the Chesapeake Group of Maryland and Virginia', Notulae Naturae, No. 469 (1988), p. 1, available on line here
