Ultrastructure de l'ectoderme des tentacules labiaux et marginaux de Pachycerianthus fimbriatus McMurrich

Abstract

In Pachycerianthus fimbriatus McMurrich, collar cells have been found in the ectoderm layer of marginal and labial tentacles. Villi, nematocytes, spirocysts, two types of mucous gland cells, and trypsinogen gland cells have been described. We have failed to discover special apical structures linked with the uptake of ferritin in solution. The rôle of apical villi and collar cells is discussed.