A sheath or outer covering, especially around the spinal cord or over the hindwings of certain insects
In a corner, the Darkling Beetle rustles in its Cage, its Elytra the same unforgiving white as the great sand-waste call’d ‘Kalahari’ lying north of here.
{i} leathery fore wings of beetles and some other insects, meeting in a straight line and serving as protective covers for the hind wings when at rest (Biology)