The Collaborative International Dictionary
Retineum
Retineum \Ret`i*ne"um\, n.; pl. Retinea. [NL. See Retina.] (Zo["o]l.) That part of the eye of an invertebrate which corresponds in function with the retina of a vertebrate.
Wiktionary
retineum
n. (context zoology English) Part of the eye of an invertebrate which corresponds in function with the retina of a vertebrate.