THE LIFE HISTORY, DEVELOPMENTAL STAGES, AND TAXONOMIC RELATIONS OF THE DIGENETIC TREMATODE LASIOTOCUS MINUTUS (MANTER, 1931) THOMAS, l959

¹ The American Museum of Natural History, Central Park West at 79th Street, New York, N. Y. 10024; and the Marine Biological Laboratory, Woods Hole, Massachusetts 02543

Cercaria adranocerca n. sp. was described by Stunkard and Uzmann (1959) from the clam Gemma gemma at Boothbay Harbor, Maine. Further study of the species at Woods Hole, Massachusetts, has afforded information for revision and correction of the original description. The cercariae are microcercous and after emergence from their sporocysts are encysted in the haemocoele of the clam. They may be extruded, either singly or embedded in a jelly-like matrix, and float in seawater. Feeding metacercariae to Menidia menidia yielded developmental stages to mature worms, identified as Lasiotocus minutus (Manter, 1931) Thomas, 1959. Discovery of the life cycle may aid in resolution of the controversy concerning the status of the genera Lasiotocus Looss, 1907; Genolopa Linton, 1910; and Proctotrema Odhner, 1911.