From scholia to Aristophanes, Acharnians 1076 (web address 1), where the festival is mentioned; see also the scholia to Aristophanes, Frogs 218 (web address 2).
[1] For the Pitchers festival, Choes, see chi 369 and chi 370. Both the Pots and the Pitchers are parts of the Anthesteria, on which see alpha 2500, theta 598.
[2] FGrH 115 F347. For this worldwide flood, associated with the name of Deucalion, cf. beta 478, theta 114, nu 24, tau 71, upsilon 68. As Jacoby notes, a longer version of the citation of Theopompus in the scholia to Frogs 218 makes it clear that qu/ein toi=s *xou=sin *(ermh=| *xqoni/w| ('that they sacrifice in the Pitchers to Chthonic Hermes'), both here and in the scholia to Acharnians 1076, is a mistake for qu/ein au)toi=s e)/qos e)/xousin ... *(ermh=| *xqoni/w| ('it is customary for them in the course of the festival (sc. the Pots) to sacrifice ... to Chthonic Hermes').