pigment cell tertiary pigment cell Interommatidial pigment cell that lies between the vertices of adjacent ommatidia. Except at the margins of the eye, vertices alternate between those with tertiary pigment cells and those with bristles. Vertices at the margins all have tertiary pigment cells. These cells contain the red screening pigment pteridine, as well as ommochrome granules. Together with secondary pigment cells, it secretes the lens between the facets. VFB:FBbt_00004233 fly_anatomy.ontology FBbt:00004233 interommatidial cell