part of neuropil glial cell brain epithelial glial cell fly_anatomy.ontology FBbt:00005721 VFB:FBbt_00005721 Cuboidal glial cell found in the visual system of larvae and adults, located more distal than the row of marginal glial cells. These glial cells contact marginal glia at their base (proximal) and satellite glia at their apex (distal), and constitute the only class of cells with nuclei in the neuropil proper, in the distal lamina.