Nine species of Monogenea of the subfamily Ancyrocephalinae were collected from Lepomis macrochirus in Walter F. George Reservoir at 2 week intervals from December 1967 to January 1969. The abundance patterns and size of the organism formed three distinct groups: (1) The large species most abundant during the autumn and least abundant during the mid summer period were Anchoradiscus triangularis and Clavunculus bifurcatus; (2) the large species most abundant during the spring and least abundant during the mid summer period were Lyrodiscus seminolensis and Cleidodiscus robustus; and (3) the small species abundant during the summer but having a prewinter peak at water temperatures near 10 C were Actinocleidus fergusoni, Urocleidus dispar, U. ferox, U. acer and Cleidodiscus nematocirrus.