Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Hellē, ēs (gen. Hellis, Sid. Carm. 9, 41), f., = Ἕλλη, daughter of Athamas and Nephele, sister of Phrixus; she fled with the latter from her step-mother Ino on a ram with a golden fleece to Colchis, but was drowned in the strait called, after her, Hellespontus (the sea of Helle), Ov. M. 11, 195; id. F. 3, 857 sq.; Prop. 2, 26, 5 (3, 21, 5 M.); 3 (4), 22, 5; Col. poët. 10, 155; Hyg. Fab. 2 and 3: Mater Helles, Ov. H. 19, 123.