Perdita belongs to Portia Group of moons , which also includes Bianca , Cressida , Desdemona , Portia , Juliet , Cupid , Rosalind and Belinda . Perdita belongs to Portia Group of satellites , which also includes Bianca , Cressida , Desdemona , Portia , Juliet , Cupid , Rosalind and Belinda .