In a deep skillet, heat 1/4 inch of the vegetable oil until very hot.
While oil is heating, whisk the egg whites in a pie plate and set aside. In another pie plate, whisk together the flour, cornmeal, salt and pepper.
When oil is ready, dip each oyster into egg whites, drain and then roll in flour mixture. Be sure all sides of oysters are coated with flour. Shake oysters lightly to remove excess flour and carefully arrange oysters in hot oil.
When arranging oysters in pan, begin at outer edge and lay oysters in a ring around outside of pan. Place a few oysters in center. Do not crowd pan. When you finish laying out oysters, first ones will be ready to turn. Turn all oysters and cook just until they turn golden-brown, for about 2 minutes total. Remove oysters from oil, drain on paper towels and keep warm. Continue with remaining oysters, if needed; discard any remaining egg whites and flour mixture.
Divide the arugula among serving plates. Divide fried oysters between portions of arugula, drizzle each plate with some of the Lemon Dressing and serve immediately with a lemon wedge on the side.
Lemon Dressing: In a small bowl, whisk together olive oil, Meyer lemon juice, grated Parmesan and minced garlic. Taste for seasoning, adding salt and freshly ground pepper to taste. May be made ahead and refrigerated for up to 1 week. Bring to room temperature before using.