The position of the helictoglossa in E. papilioforma may be more removed (central) from the apex, as in E. incisa. Valves of E. incisa, however, are symmetrical in regard to apex width and position of the helictoglossae. The type illustrations of E. rhomboidea are more or less asymmetrical about the transapical axis (Simonsen 1987, Plate 546), but in comparison to E. rhomboidea, E. papilioforma valves are consistently wider.