Apollodorus 2.1.5
Ten sons of Aegyptus by an arabian woman married ten daughters of Danaus by Hamadryad nymphs, some daughters of Atlanteia and others of Phoebe. Istrus married Hippodamia.
Some have objected to the presence of two Hippodameiae in this group. The footnote to 2.1.5 in Frazer's edition (1921) of Apollodorus directs our attention to Pausanias 4.30.2, which mentions a Phylodameia as a daughter of Danaus, and to Hyginus, Fab.170, on the basis of which "Wagner conjectured Hippothoe." But Danaus had, in addition to the Cleopatra who married Agenor, another daughter named Cleopatra by Polyxo, and two daughters named Evippe, one by an Ethiopian woman, the other by Polyxo. Furthermore, Aegyptus had two sons named Daiphron. From this we can see that half-siblings may have the same name. Therefore, it could easily be that one Hippodameia was the daughter of Atlanteia, and the other Hippodameia was the daughter of Phoebe.