Like the fourth circle of hell, the fifth circle–presented in Inferno 7 and 8–contains two related groups of sinners. But whereas avarice and prodigality are two distinct sins based on the same principle (an immoderate attitude toward material wealth), wrath and sullenness are basically two forms of a single sin: anger that is expressed (wrath) and anger that is repressed (sullenness). This idea that anger takes various forms is common in ancient and medieval thought. Note how the two groups suffer different punishments appropriate to their type of anger–the wrathful ruthlessly attacking one another and the sullen stewing below the surface of the muddy swamp (Inf. 7.109-26)–even though they are all confined to Styx.
 
Bron: danteworlds.laits.utexas.edu