Graces.
According to most mythographers, the Graces (Greek, Χάριτες=Charites) were daughters of Zeus and the Oceanid Eurynome. Typically three in number, they personified grace, charm, and beauty and were called Aglaia (Splendor), Euphrosyne (Mirth), and Thalia (Abundance). Although they usually accompanied the Muses, Aphrodite (Venus), and Eros (Cupid), they could also be found in association with almost any of the Olympian deities; legends link them to Athena (Minerva), Hephaestus, and others.
       In the Classical period, the Graces were depicted as clothed young women, but by the Hellenistic era they were frequently nude, a tradition continued by Roman artists. During the Roman era, the Graces (Latin, Gratiae) were also the symbol of gratitude and were called Castitas (Chastity), Voluptas (Pleasure), and Pulchritudo (Beauty). Postclassical depictions of the Graces—comely figures in a circle— derive direcdy from the andque model.
      

Further Reference: Wind, Edgar. 1968. Pagan Mysteries in the Renaissance. Rev. ed. New York: Norton. (Chapters 2 and 3)

See also Aphrodite; Ares and Aphrodite; Eros; Punishment of Eros; Hermes; Pandora; and Parnassus.