There is a comprehensive phylogeny and new classification of Acoela published in 2011. It should be reflected in the EOL taxonomy. Jondelius, U., Wallberg, A., Hooge, M., & Raikova, O. I. (2011). How the Worm Got its Pharynx: Phylogeny, Classification and Bayesian assessment of Character Evolution in Acoela. Systematic Biology, 60(6), 845–871. Oxford University Press.