A new species of Proterometra, P. edneyi n. sp., is described and illustrated. Under laboratory conditions, the cercaria emerges from the snail host, Goniobasis semicarinata, between 1000 and 1800 hours. Behavior of this small distinctive cercaria consists of irregular, worm-like movements which rarely propel it through the water. Correspondingly, little acetycholinesterase activity is localized histochemically in that region of the tail where flexions occur. The adult differs from the seven previously known species in being the smallest in size and having the fewest number of eggs in utero. This is the first species of Proterometra reported to use a darter fish, Etheostoma sp. (Percidae), rather than a sunfish (Centrarchidae) as the final host.