Of the umbrella, EU, Ve, Fr, Tc, The ocelli vary greatly both as regards number and complexity of structure.
As a further advance, the pit becomes widened out into a cup, as in the lateral ocelli of Charybdaea.
The sense-organs of medusae are of two kinds - first, organs sensitive to light, usually termed ocelli (fig.
Inner lobe of large and convex; three ocelli ' left maxilla).
The head is rather large, and is furnished at first with five simple eyes of nearly equal size; but as it increases in size the homologues of the facetted eyes of the imago become larger, whereas those equivalent to the ocelli remain small.
In other cases ocelli may occur between tentacles, as in Tiaropsis (fig.
Most insects possess a pair of compound eyes, and many have, in addition, three simple eyes or ocelli on the vertex.
The culminating stage of evolution is seen in the median ocelli of Charybdaea (fig.
X Ocelli and post-antennal organ of right side.
The ocelli consist, as c, From the subumbrella of Aurelia aurita.