noun. In zoöl. and anat.:

noun. The cuticle proper; the epidermis; the ectoderm; the exoskeleton; the superficial investment of the body, in so far as this is formed by or derived from the epiblastic cells or epiblast of the embryo, whatever its ulterior modification.

noun. In infuserians, a comparatively dense envelop to which the outer wall of the body gives rise. Also cuticulum.

noun. In annelids, as the earthworm, a thin and transparent though tough membrane, forming the outermost envelop of the body, and perforated by extremely minute vertical canals.

noun. the outer body wall of an insect.

noun. A tough protective covering outside the epidermis of many invertebrates and plants; cuticle.

noun. the outer body wall of an insect

"This is known as the cuticula dentis, or Nasmyth’s membrane, and is believed to be the last-formed layer of enamel derived from the adamantoblasts, which has not become calcified."