The shell is external, thin, fragile, pellucid and shining, convolute and globose. The shell is subglobose, somewhat smooth, pellucid and greenish hyaline in colour. The female moths lay pellucid green eggs. The word "pellucid" means clear, indicating that the corneas retain clarity in pellucid marginal degeneration. Birds chattered in the trees and big fish darted through the pellucid depths. Volucella pellucens, the pellucid fly, is a hoverfly. The early stages of pellucid marginal degeneration may also be managed with soft contact lenses. The leaves are rigid, coriaceous and often have pellucid dots. Molluscs recorded include the Roman snail and the great pellucid glass snail. Pellucid marginal degeneration is diagnosed by corneal topography. The hindwings are grey, thinly scaled and pellucid in the disc and towards the base. The Jialing River's most notable characteristic was formerly its pellucid green waters. This, however, allows the "patterns [to] crystallize with pellucid clarity [very clear, transparently clear]". At first it is whitish and pellucid, but afterwards it becomes harder and reddish. The term "pellucid marginal degeneration" was first coined in 1957 by the ophthalmologist Schalaeppi.