Dicrocoeliidae

noun plural

Di·​cro·​coe·​li·​i·​dae ˌdī-krə-sə-ˈlī-ə-ˌdē 

: a family of small to medium-sized flattened or more or less cylindrical digenetic trematode worms that as adults parasitize the biliary ducts or occasionally other viscera of vertebrates