title: Fine structure of the cerebral ocelli of a sipunculid, Phascolosoma agassizii.
mesh_terms: D000818:Animals; D000845:Annelida / Q000166:cytology*; D002490:Central Nervous System / Q000166:cytology*; D002923:Cilia; D003594:Cytoplasmic Granules; D006652:Histological Techniques; D008854:Microscopy, Electron; D011984:Sensory Receptor Cells / Q000166:cytology