Cover crabs with boiling salt water and boil for 30 minutes. Drain off the water, break off all claws, separate the shells and remove the spongy fingers and the stomach, which is found under the head. Pick out all the meat and set aside. Clean the upper shells of the crabs thoroughly. Melt the butter and add the flour and blend. Stir in cream and cook until mixture thickens, stirring constantly. Add the parsley, mashed egg yolks, seasonings and crab meat. Fill the shells with this mixture and cover with bread crumbs. Bake at 350-F for 10 minutes or put in a frying basket and plunge into hot oil until golden brown.