Principal Dawson, of Montreal,. Canada, has placed in my hands for description a remarkably interesting specimen, indicating a species of the genus Cephalaspis in transatlantic Silurio-Devonian beds. He writes, “The specimen was found by one of my assistants, Mr. G. F. Kennedy, B.A., when collecting with me, in a bed charged with remains of Psilophyton, on the north side of Gaspé Bay. The geological horizon is below the middle of the Gaspé Sandstones, but several hundreds of feet above their actual base, so that the specimen may be regarded as either Lower Devonian or Lower Middle Devonian.