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.

Ultrastructural study of the spermatogenesis and mature spermatozoa of Dicrocoelium dendriticum (Plathelminthes, Digenea).

The spermatogenesis and spermatozoon of Dicrocoelium dendriticum were studied by transmission electron microscopy. Peripheric accessory cells project between germ cells. Each spermatogonium gives rise to 32 spermatozoa.

Intracytoplasmic ciliary elements in epidermal cells of Syndesmis echinorum and Paravortex cardii (Platyhelminthes, Dalyellioida).

Epidermal cells of Syndesmis echinorum and Paravortex cardii contain many intracytoplasmic ciliary components: clusters of centrioles disorganized and incomplete short axonemes composed of loosely organized microtubules of irregular lengths, fully formed axonemes though some with fewer than nine doublets, and ciliary rootlets. Furthermore, conspicuous dense granules are found in solitary groups in the cytoplasm. Clusters of dense granules are also closely associated with Golgi complexes and developing axonemal microtubules.

Scanning electron microscopy of adult Dicrocoelium dendriticum.

Scanning electron microscopy (SEM) has been used to study the tegument and related structures of adult Dicrocoelium dendriticum. Its body shape, suckers, common genital pore, Laurer's canal pore, excretory pore, and cirrus are described as seen under SEM. The tegument is devoid of spines and presents an interlacing, ridged network which covers the entire body.