Fig. 9.

Magelona mirabilis, ultrastructure of the giant fibre. A-C 70 nm, a,b cross section, c sagittal section. a: the giant fibre (gf) is surrounded by a prominent layer of glia cell processes (gcp) which contain numerous gliosomes (gl). Nuclei (ngc) of the glia cells are located between the giant fibre and the neurites (ne) of the neuropil. b: The giant fibre (gf) is coated by a membrane (mgf) and separated from the neuropil by glia cell processes (gcp) which contain gliosomes (gl). c: The cytoplasm of the giant fibre (gf) contains numerous mitochondria (mt), lucent (lcv) and dense core vesicles (dcv). gc: glial cell; mgf: membrane of giant fibre