Thebis Proteus filiam habuit Galinthiadem, ludi et vitae soliditate iunctam virginem Alcumenae, filiae Electrionis. Cum parturiret Alcmena Herculem, Parcae et Lucina in gratiam Iunonis eam in doloribus detinuerunt, manibus suis constrictis sedentes. Ibi Galinthias verita ne ex doloribus moreretur Alcmena, ad Parcas et Lucinam accurrit, nuncians Iovis voluntate puerum ab Alcmena partu editum, actumqe esse de ipsarum honoribus. Ad hoc obstupuerunt Parcae, statimque manus dimiserunt. Illico etiam Alcmena soluta doloribus, Herculem est enixa. Ad hoc Parcae luctum instituerunt: et Galinthiadi, quod mortalis deas decepisset, virginitatem ademerunt, inque fraudulentam mutaverunt felem.
--Antoninus Liberalis, Metamorphoses XXIX, trans. from the Greek by Wilhelm Xylander
The Theban Proteus had a daughter named Galinthias, who was inseparable from her dear friend Alcmena (Electrion's daughter). When Alcmena was pregnant with Hercules, Juno's henchmen Lucina [goddess of childbirth] and the Fates beset her limbs to keep her from giving birth. Fearing that Alcmena would die in childbirth, Galinthias ran up to the goddesses and thanked them, proclaiming that Alcmena had already given birth by the will of Jupiter. Hearing this, the goddesses were thunderstruck, and released Alcmena in their daze. Once she was free from their control, Alcmena was able to give birth to Hercules. Angered that a mortal had deceived them, the goddesses smote Galinthias, stripping her of her womanly shape and turning her into a [pole]cat.