ALCYO´NIA(Ἀλκυονία), a lake in Argolis, near the Lernaean grove, through which Dionysus was said to have descended to the lower world, in order to bring back Semele from Hades. Pausanias says that its depth was unfathomable, and that Nero had let down several stadia of rope, loaded with lead, without finding a bottom. As Pausanias does not mention a lake Lerna, but only a district of this name, it is probable that the lake called Alcyonia by Pausanias is the same as the Lerna of other writers. (Paus. 2.37.5, seq.; Leake, Morea, vol. 2. p. 473.）