1 c. crabmeat
2 c. frozen shrimp
1 pt. Hellmann's mayonnaise
2 c. diced celery
1 med. onion
1 c. mushrooms
1 tsp. salt
1 tsp. pepper
1 can sliced water chestnuts

Put in buttered casserole and top with crumbs. Bake at 350 degrees for 30 minutes.