In a medium bowl mix crab-meat, green onions, herbs and pepper. Mix in the mayo and 1/4 cup parmesan cheese until thoroughly combined. Store in the refrigerator until ready to use.
Wipe the mushrooms clean with a damp towel. Remove the stems and scoop out insides with a melon baller. Fill the mushroom caps with rounded teaspoons of the filling, and place them on an ungreased shallow baking dish. Sprinkle the tops with the parmesan cheese and paprika.
Bake for 15 minutes. Remove from the oven and serve immediately.