hyla's lethe-->lethargic and Mnemosyne-->mnemonic led me to wonder what other common words were derived from the rivers separating Hades from the living world (i was thinking perhaps "stigma" is derived somehow from Stygian/Styx?) unfortunately, Google turned up only a ton of anime (Sailor Moon) links, and now i'm curious about the names of the rivers themselves; my search yielded Acheron - the river of woe; Cocytus - the river of lamentation; Phlegethon - the river of fire; Lethe - the river of forgetfulness; Styx - the river of hate, but mentioned Mnemosyne only as one of the Muses who guarded the river of memory. the river itself is not named (or it is simply Mnemosyne?). has anyone a good link that will make this clear?

TIA
b