Mash 1 cup of blueberries. In 2 litre saucepan, stir together sugar and cornstarch. Gradually stir in the water until smooth. Stir in mashed blueberries and lemon rind. Cook over medium heat, stirring, until thickened and boiling. Boil 1 minute. Turn into a bowl; cover with wax paper. Cool. Fold in remaining berries. Whip cream until double in volume. Spread 1.5 cup of whipped cream over bottom and up sides of pie shell. Fill with blueberry mixture. Garnish with remaining whipped cream. Chill until set -about 3 hours.