Set ¼ cup corn aside. In a medium saucepan, bring the rest of the corn and the milk to boil. Cover and remove from heat. Let stand for 10 minutes. Purée the corn mixture in the blender. Add the clam juice, 3 tablespoons green onions, and 1 teaspoon ginger; purée again until almost smooth. Return purée to saucepan; bring to simmer. Mix in 1½ teaspoons lemon juice. Season with salt and pepper.
Melt the butter in a small skillet over medium heat. Add reserved ¼ cup corn; sauté 1 minute. Add crab, 1 tablespoon green onions, 1 teaspoon ginger, and 3 teaspoons lemon juice; stir just until warm. Season with salt and pepper.
Divide the soup among 4 bowls; mound the crab mixture in the center of each bowl.
Notes
Garnish with oyster crackers (not included in nutritional information)
If you are preparing this recipe as GLUTEN-FREE, just be sure to use clam juice that is known to be free of gluten.