Ptyalincola gen. n. is erected, with P. ondatrae sp. n. as the type, for trematodes found naturally and experimentally in the muskrat, Ondatra zibethicus, in Michigan. The sites of infection, salivary and other oral glands, have not been cited heretofore as loci for flukes. Freshwater mussels, especially Anodonta grandis, serve as the molluscan hosts for the infective unencysted metacercarial stages. Ptyalincola ondatrae resembles Leucochloridiomorpha constantiae in utilization of aquatic mollusks as secondary intermediate hosts, but differs from the latter in morphology. The subfamily Leucochloridiomorphinae is emended to include both of these genera.