The structure of the eye of Ligia oceanica L.

There are eight retinula cells in each ommatidium. Two of these cells are half the size of the others, and there is a small basal cell with large vesicles in its cytoplasm but no rhabdomere. The rbabdomeres are separate and the cytoplasm of the basal cell extends into the space between them at the central end. The rhabdomere tubules are regularly arranged at the periphery and irregular at the central end. The extent of irregular arrangement is increased if animal is kept in dark. There are eight axons from each ommatidium.