1. Head with three prominent ocellar tubercles (Fig.1.1); maxillary and labial palpi two segmented; forelegs distinctly shorter than middle and hind legs (Fig.1.2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sparbarus
Head without ocellar tubercles (Fig.1.3); maxillary and labial palpi three segmented; forelegs subequal in length to middle and hind legs (Fig.1.4). . . . . . . . . . . . . . Caenis
Key to Ohio Caenidae Nymph Genera
