Junctional structures in the crystalline cone of the crayfish compound eye.

The junction in the crystalline cone in the compound eye of the crayfish Procambarus clarki is described. It consists of electron-dense pentahedrons arranged regularly all over the cytoplasmic surface of each membrane and dense material in the intercellular space. The cone is an entity formed by the secretion of the four cone cells so the junctional structures may serve a cohesive function. This junction is therefore designated as a coherent junction.