1. Posterior sucker without a marginal circle of gland or retractile papillae (digitate processes). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Posterior sucker conspicuous with a marginal circle of 30-60 glands and retractile papillae (digfitate processes), their positions being indicated dorsally by faint radiating ridges.. . . . . . . . . . . . . . Actinobdella inequiannulata
2. Zero, one, or two pairs of eyes; a series of paired accessory eyes sometimes present along body. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Three or 4 pairs of eyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Eyes closely set together (separated by less than the diameter of one eye, touching, or coalesced); proboscis pore (mouth) apical or subapical on rim of anterior sucker or just below rim of anterior sucker. Two pairs of eyes (one pair large on segment III and one poir small on segment II); eyes close together or confluent (except Placobdella monifera, which have eyes well separated); male and female gonophoes separated by two annuli; body usually papillated; seven pairs of crop caeca; bifurcated ovisacs. . . . . . . . . . . . . . Placobdella
Eyes distinctly separated or separated by at least the diameter of one eye; proboscis pore (mouth) within anterior sucker and clearly not on rim. Gonopores separated by one annulus. . . . . . . . . . . . . . . . . . . . .Helobdella
4. Eyes equidistant in two paramedian rows. . . . Glossiphonia complanata*
First pair of eyes closer together than succeeding two pairs, i.e., eyes arrranged in triangular pattern; not papillae; male and femele ducts open inot a comon gonopore; little pigmentation; generall amber colored; length 10 mm. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alboglossiphonia heteroclita*not known in Ohio.