In a stockpot, combine the backbones, onion, butter, and seasonings. Add the water, bring to a boil, cover, and cook at a low boil for 40 minutes. Add the rice to the pot and return to a boil, stirring well. Boil for 10 minutes, then reduce the heat, add green onions, cover the pot, and simmer for 10 minutes or until rice is done. Remove the bay leaves and serve.