Preparation:

1. Make the dressing: Whisk the olive oil, vinegar, lemon juice, parsley, salt and pepper in a large bowl until blended. Crush the shallots and garlic with the flat side of a knife, add them to the dressing; set aside. 2. Bring two large pots and two medium saucepans of salted water to a boil. Add one-half lemon to each. Cook the seafood as described below; remove each with a slotted spoon and set aside to cool as soon as it is cooked --with the exception of the shrimp. (See below) 3. Place the octopus and scungilli in one of the large pots. Adjust the heat to simmering and cook until tender, about 40 minutes. Place the lobster, head first, into the other large pot of boiling water. Cover the pot and cook 8 minutes. Place the calamari into one of the medium saucepans, and adjust the heat to low. Simmer until tender, about 20 minutes. Place the shrimp in the other medium saucepan and boil just until cooked through, 4 to 5 minutes. Remove the shrimp with a slotted spoon to a bowl of ice water to stop the cooking. Add the scallops to the same pot and cook 4 to 5 minutes, remove with slotted spoon to ice water. 4. When the seafood is cool enough to handle, prepare each as follows: To clean the scungilli, cut along the outer curved side until you reach the digestive tract, a thin dark sac that runs from the middle of the body to the tail. Pull or scrape out the sac; slice the scungilli on the diagonal into very thin slices. Cut the tentacles from the octopus, and cut each tentacle diagonally into two pieces. Cut the head into 4 or 5 pieces. Remove the lobster meat from the tail and slice it crosswise into 1/2 inch medallions. Remove the meat from the two "knuckles" of each claw and leave them whole. Remove the meat from the claws, pull out the piece of cartilage and cut each claw in half lengthwise. Remove all shells from the shrimp. Make a shallow cut along the length of the outside of the shrimp and scrape away any traces of the sand vein. Cut the shrimp in half lengthwise. Leave the scallops and calamari as is. 5. Add each type of seafood to the dressing as you prepare it. Toss well, cover the bowl and refrigerate up to 2 hours. Toss the salad, check the seasoning and adjust if necessary before serving. Arrange the salad in a serving bowl or platter; scatter the celery, olives and cherry tomatoes around; garnish with lemon wedges and parsley springs.
Per Serving: 409 Calories (46.3% from fat); 21g Fat (2g Sat, 10g Mono, 2g Poly); 43g Protein; 12g Carbohydrate; 1g Dietary Fiber; 266mg Cholesterol; 1225mg Sodium.  Food Exchanges: 0 Grain (Starch); 6 Lean Meat; 1/2 Vegetable; 1/2 Fruit; 4 Fat.