1. Wash fresh scallops under cold running water or partly thaw frozen ones; cut into quarters.
2. Combine onion and lemon slices, salt and water in a medium-size saucepan; heat to boiling; add scallops; cover. Remove from heat; let stand 5 minutes; drain.
3. Place scallops in a small bowl; drizzle Italian dressing over; toss to mix. Cover; chill.
4. When ready to serve, dip scallops into parsley, place each on a wooden pick and stick into a half slice of lime.