What can be the nature of that singular lid whereof the Cerambyx furnishes me with the first specimen?
It is as hard and brittle as a flake of lime-stone.

It can be dissolved cold in nitric acid, discharging little gaseous bubbles.

The process of solution is a slow one, requiring several hours for a tiny fragment.

Everything is dissolved, except a few yellowish flocks, which appear to be of an organic nature.

As a matter of fact, a piece of the hatch, when subjected to heat, blackens, proving the presence of an organic glue cementing the mineral matter.