Ultrastructural study of sensory cells of the proboscidial glandular epithelium of Riseriellus occultus (Nemertea, Heteronemertea).

Only one sensory cell type has been observed within the glandular epithelium of the proboscis in the heteronemertine Riseriellus occultus. These bipolar cells are abundant and scattered singly throughout the proboscis length. The apical surface of each dendrite bears a single cilium enclosed by a ring of six to eight prominent microvilli. The cilium has the… (More)