Preheat oven to 350°. In large mixing bowl, stir together sugar, flour and nutmeg.
In small bowl beat eggs and milk until mixed. Add to sugar mixture and stir until smooth. Fold in rhubarb. Spoon rhubarb mixture into pie shell. Dot with butter. Cover edge with foil.
Bake 25 minutes. Remove foil; bake 30 to 35 minutes more or until knife inserted in center comes out clean. Cool on wire rack. Store leftover pie in refrigerator