Saute onion, celery, and green pepper in 3 tbsp. butter over medium high heat until vegetables are tender and slightly browned. About 3-5 minutes.
Stir in flour, cheese, salt, pepper and Worcestershire sauce. Add 1/4 cup of Ritz crackers and mix thoroughly.
Stir in clams with their liquid, stirring while you cook until mixture is thick and bubbly. Add parsley (reserving a little for garnish). Divide mixture evenly among 10-12 clam shells.
Combine remaining crumbs and 1 tbsp. melted butter and sprinkle over the filled shells. Sprinkle lightly with paprika and remaining parsley.
Bake at 350 degrees F. for 12-15 minutes. Serve hot.