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