Note 22 — TRILOBITES, &c.

We have seen in the Cabinet of Mr. Featherstonhaugh, a fine group of trilobites, in the transition limestone, from Dudley, (Eng.) Among them there is a perfect head, which agrees exactly with the description given by Mr. Brongniart of the head of his Calymene Macrophthalma. If this belongs to the true macrophthalma, our species under that name is entirely distinct. Since our work had been prepared for the press, Dr. J. J. Cohen, of the Baltimore College, has shown us the fragment of a calymene from Berkley, Virginia, which agrees with Brongniart's description of the macrophthalma, and with the above fossil from Dudley. We regret that the imperfection of the fossil prevents our giving a satisfactory cast of it.