4. Plutarch (Plut. Alex. 41) mentions Ephialtes and Cissus as those who brought to Alexander the intelligence of the treachery and flight of Harpalus in B. C. 324, and were thrown into prison by the king as guilty of calumny. The play of the comic poet Phrynichus, called " Ephialtes," does not seem to have had reference to any of the above persons, but rather to the Nightmare. (Meineke, Hist. Crit. Com. Graec. pp. 152-154.)
[E.E]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890