Pronunciation: (ri-tin'yu-lu), [key]
—pl. -laePronunciation: (-lē"). [key]
a group of elongate neural receptor cells forming part of an arthropod compound eye: each retinula cell leads to a nerve fiber passing to the optic ganglion.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.