Up to December last the most ancient fossil insects known were the six fragments of Neuroptera, obtained by Mr. C. F. Hartt, from the Devonian rocks of New Brunswick, which were described by Mr. Scudder in Vol. V. of this Magazine. Although these six fossils were the oldest known insects, it seemed unlikely that they, or even the families or genera to which they belonged, were the most ancient representatives of their class. The first appearance of insects on the Earth was probably contemporaneous with that of land plants, and as remains of this division of the Vegetable Kingdom had been discovered in Silurian rocks, it seemed not unreasonable to assume that insects might have existed at an earlier period than the Devonian. The recent discovery of the wing of a cockroach in rocks of Silurian age at Jurques, Calvados, France, no longer leaves the question of the occurrence of insects at an earlier period than the Devonian a matter of speculation.