Melt the butter in a saucepan, sauté the garlic for several minutes, then add the lemon juice and a little salt. Preheat the broiler. Place the split rock shrimp shell side down in a broiling pan. Baste each shrimp heavily with the butter mixture. Sprinkle with paprika. Broil 4 inches from the heat for 2 or 3 minutes. Do not overcook. Serve hot, along with small forks for removing the meat from the tails.