- Single Ommatidium of Cockroach's Eye (after Grenacher).
The lateral eyes of Scorpio consist of groups of separate small lenses each with its ommatidium, but they do not form a continuous compound eye as in Limulus.
The ommatidium (soft structure beneath the lens-unit of a compound eye) is very simple in both Scorpio and Limulus.
The cells of tl ommatidium are a good deal larger than the neighbouring common cells of the epidermis.
23) each ommatidium has a peculiar ganglion cell developed in a central position, whilst the ommatidium of the lateral eyelets of Scorpio shows!
That the lateral eyes of Scorpio have a single cell-layered or " monostichous " ommatidium like that of Limulus.