EXTRA-ECTODERMAL STRANDS IN THE CILIATED BANDS OF THE ECHINOPLUTEUS

Abstract
An ectodermal nerve net and some extra-ectodermal, axon-like elements were demonstrated in the ciliated bands of Psammechinus miliaris larvae. These extra-ectodermal structures, together with the microvillous epithelial cells and the ectodermal nerves probably participate in the co-ordination of responses on external sensory stimulation.