Schematic representation of tentacular and mesenterial arrangements. A Scolanthus armatus and S. kopepe sp. n. B S. ena sp. n. C S. isei sp. n. Abbreviations: a, actinopharynx; bw: body wall; dd, dorsal directive; dlm, dorso-lateral mesentery; mi, microcneme; rm, retractor muscle; vd, ventral directive; vlm, ventro-lateral directive. White circles indicate the locus of tentacles.