In the course of an investigation of the cause of sickness and death among Canada geese in their overwintering grounds, carried on jointly by the Parasite Research Laboratory, Animal Disease and Parasite Research Branch and the Disease Laboratory, U. S. Fish and Wildlife Service, a blood fluke belonging to the genus Trichobilharzia was discovered. The species appears to be new, and for it the name T. brantae is proposed. The long fragile flukes were difficult to remove intact, since they usually occurred in a network of veins. One specimen was removed from the mesenteric veins and the remaining specimens from the kidney veins. Occasionally a tangled knot of males and females was enmeshed within a vein in a gelatinous substance in which were also trapped numbers of eggs (Fig. A).