Fill a large (10-quart) stockpot one-third full with water. Add the lemons, potatoes, corn, onions, salt, and peppers. Cover and bring to a boil over high heat. Let boil for 10 minutes. Add the crabs, (if blue crabs are not available, substitute other small to medium crabs), cover, and return to boil. Once steam starts to escape from under the cover, let cook for 15 minutes. Turn off the heat and let sit, covered, for 10 minutes more. From Alex Patout's "Cajun Home Cooking" Published by Randon House Alex says, "Serves 2 Cajuns, 4 elsewhere." He writes, "We like to lay out the crabs and vegetables on a large table covered with lots of paper and have a feast."