Cover illustration. Myzostomida are an enigmatic subgroup of Annelida which diverged early during the phylogeny of annelids. Adult myzostomids show a highly specialized body plan, which lacks many of the typical annelid features. In this issue of the Journal of Morphology Helm et al. (pp. 456–466) report about an analysis of the musculature system of Myzostoma cirriferum using confocal laser-scanning microscopy. They support the annelid affinity of myzostomids and suggest that the apparent partial radial symmetry of M. cirriferum arose secondarily in this species.