1. Lamellae of first pair of gills each with large anterior expansion, usually meeting or nearly meeting ventrally. Abdomen with at least terga 3-7 having paired submedian dark spots (sometimes faint); mature body length usually over 9.84 mm (not including cerci). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Epeorus pleuralis
Lamellae of first pair of gills only slightly expanded anteriorly; lacks paired submedian dark spots on terga 3-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Epeorus namatus
Key to Ohio Epeorus Nymph Species