Taken from Norms for the Distribution of Holy Communion Under Both Kinds

41. Holy Communion under the form of bread is offered to the communicant with the words "The Body of Christ." The communicant may choose whether to receive the Body of Christ in the hand or on the tongue.

When receiving in the hand, the communicant should be guided by the words of St. Cyril of Jerusalem:
    "When you approach, take care not to do so with your hand stretched out and your fingers open or apart, but rather place your left hand as a throne beneath your right, as befits one who is about to receive the King. Then receive him, taking care that nothing is lost."