Mesures dominées par une capacité alternée d'ordre $2$

Let C be an alternating capacity of order 2 on a metrizable compact space, and let ${\mathcal{P}_C}$ be the convex set of all measures dominated by C. We find a quite simple set of extreme elements of ${\mathcal{P}_C}$ such that the closed convex hull of this set is ${\mathcal{P}_C}$. We also give other properties, including a generalization of one of Anger's results.