During a routine examination for larval trematodes of a collection of Lymnaea stagnalis apressa Say from Douglas Lake, Michigan, a snail was discovered that harbored a double infection of strigeoids, viz, Diplostomum flexicaudum (Cort and Brooks, 1928) and Cotylurus flabelliformis (Faust, 1917). A mother sporocyst of C. flabelliformis was found between the body and digestive gland of this snail and was removed intact (Fig. 1). ... We know of no other instance where daughter sporocysts and cercariae have been found in the same mother sporocyst.