Retinula

noun

1. A cluster of pigment-containing photosensitive cells in each ommatidium of the compound eye of an arthropod.
2. In entomology, a group of combined retinal cells, bearing a rhabdom.
3. One of the group of pigmented cells which surround the retinophoræ of invertebrates. See Illust. under ommatidium.
4. One of the group of pigmented cells that surround the retinophorae of invertebrates.