Fig. 4 in Loss of complexity from larval towards adult nervous systems in Chaetopteridae (Chaetopteriformia, Annelida) unveils evolutionary patterns in Annelida

Fig. 4 Adult ultrastructure of the nervous system. a: The brain is intraepidermal; i.e., the neurites (ne) are located dorsal to the basal lamina (bl). Intermediate filaments (if) are located inside radial glial cell processes (gcp) which cross the neuropil perpendicularly. mu: musculature. b: Somata (so) of neurons are located dorsal to the neurites (ne). Nuclei (nu) of neuronal somata are spherical. Somata of glial cells (sogc) are interspersed between the neuronal somata (so).