part of develops from pigment cell primary pigment cell VFB:FBbt_00004231 Retinal pigment cell that is part of an ommatidium. Each ommatidium has two primary pigment cells. These cells line the pseudocone and are in contact basally with the cone cells. They contain coarse granules of ommochrome screening pigment. Along with the cone cells, they secrete the lens. FBbt:00004231 fly_anatomy.ontology ommatidium primary pigment cell precursor