Philoxenus of Cythera's dithyramb, Cyclops or Galatea, was a poem famous in antiquity as the source for the story of Polyphemus' love for the sea-nymph Galatea. The exact date of composition is uncertain, but the poem must pre-date 388 B.C., when it was parodied by Aristophanes in the parodos of Plutus (290–01), and probably, as we shall see below, post-dates 406, the point at which Dionysius I became tyrant of Syracuse (D.S. 13.95–6). The Aristophanic parody of the work may well point to a recent performance in Athens, perhaps the first, and it is hard to identify any more significant reason for mentioning the poem. Previous accounts of the poem have concentrated on two main points, its supposed satirical purpose, and the possibly dramatic nature of its performance, but there has been no attempt to consider these two points in relation to each other, or to assess in detail the value of the source-material. I argue that although there is some evidence to support the satirical reading of the poem, the main value of this tradition is that it reveals Philoxenus' comic treatment of his subject, and that while the Galatea motif has previously been considered the essential element in this comic treatment, it was probably a small part of the plot, perhaps only briefly alluded to. Finally I provide reasons for doubting the prevalent view that the performance included dramatic elements.