Rinse scallops thoroughly in cold water; drain well. Combine scallops and lime juice in a large bowl; cover and refrigerate at least 4 hours. Drain well.
Combine scallops, chiles, tomatoes, onion, olive oil, cilantro, salt, and pepper in a large bowl; stir well. Cover and chill thoroughly. Serve cold in cocktail or sherbet glasses. Garnish with avocado and lime slices.