Kittonia elaborata is a rare fossil Oamuru diatom with two ocelli. These ocelli are protrusions that originate from the main body of the diatom as tubular structures which bend outwards and terminate in flattened disc-shaped swellings that lie parallel to the valve surface and and are perforated by rows of fine pores which can be identified even at 40X, though clearer at 100X. In living diatoms, similar protrusions are involved in chain formation, which helps the organisms control their depth in water to optimize light reception for photosynthesis.
David Walker's article on Microscopist.net
The delicate nature of the ocelli feet makes undamaged specimens very rare in fossil samples. This example from another unsigned slide, in addition to missing some parts of the valve face, has only one of the two ocelli completely intact.
