Abstract
Haplocleidus dispar (Mueller, 1936) Mueller, 1937 and Pterocleidus acer (Mueller, 1936) Mueller, 1937 (Monogenea: Ancyrocephalinae) from the gills of Lepomis gibbosus L. (pumpkin-seed) in Ontario, Canada, are redescribed with details of their internal anatomy as well as the sclerotized components of the haptor and copulatory complex. Revised generic diagnoses incorporating features of the reproductive systems are presented.