Above the eggs are the curved plates, which are set very closely and have little freedom; their edges constituting the zone of issue, where they form a double series of small overlapping scales.
The eggs are set in a yellowish medium of horny appearance.

They are arranged in layers, in lines forming arcs of a circle, with the cephalic extremities converging towards the zone of issue.

This orientation tells us of the method of delivery.

The newly-born larvae will slip into the interval between two adjacent flaps or leaves, which form a prolongation of the core; they will then find a narrow passage, none too easy to effect, but sufficient, having regard to the curious provision which we shall deal with directly; they will then reach the zone of issue.

There, under the overlapping scales, two passages of exit open for each layer of eggs.