speculum

speculum (noun; plural -ula, ums; Latin diminutive specere, to look at): 1. An ocellus

See also: eyespots 2. (Arthropoda: Insecta) a. In Lepidoptera, the brilliant metallic markings, or transparent spots on the wing. b. The thin, delicate membrane of the tympanal organ. c. The shiny areas of some caterpillars. d. In ichneumonid Hymenoptera, a slight, polished or sculptured prominence on the upper hind part of the mesepisternum.