Turn tail over and cut through the underside of shell and meat. Cut each halved tail crosswise through shell and meat 3 or 4 times to make 6 or 8 pieces total. Add lobster pieces and shrimp to broth mixture. Simmer gently for 2 to 3 minutes or until shrimp just turn pink. To serve, place a bread slice into each soup bowl, if desired.
Spoon shrimp mixture atop.
Sprinkle with parsley, if desired. Makes 4 main-dish servings.