A semitransparent membrane, which can be drawn across the eye in birds and reptiles, either to moderate the effects of a strong light or to sweep particles of dust, etc. , from the surface of the eye.

The simple eyes or stemmata of insects, usually situated on the crown of the head between the great compound eyes.

The gullet.

A great series of secondary rocks, so called from the texture of some of its members, which appear to be made up of a mass of small Egg - Like calcareous bodies.