In a late number of the Magazine I mentioned that I had obtained from several of the Treshinish Islands specimens of gyrolite, and that one of these carried crystals which seemed sufficiently perfect for the determination of the form of the mineral.

A careful examination of the specimen showed it to be somewhat fragile; and, as we know that the mineral is itseff excessively tender as well as soft, I thought it desirable that the most should be made of so unique an example.