Having been engaged for some time in collecting and studying the organic remains of the Corniferous Limestone and Hamilton formation of the western portion of the Province of Ontario, I propose, in the present communication, to describe some of the new species which have come under my notice, these being chiefly referable to the groups of the Corals and the Polyzoa. A portion of the new material which I have collected I have already described in the “Annals of Natural History” and in the “Canadian Naturalist,” and a portion still remains for more extended examination. Some of the species here described, also, will be fully illustrated in the detailed Report on the Devonian Fossils of Western Canada, which I am now preparing for the Government of the Province of Ontario. Under any circumstances, the Corniferous and Hamilton deposits of Western Canada are so richly fossiliferous, that more extensive investigations than I have been able to carry out would certainly result in the bringing to light of numerous new forms of animal life. The total number of species comprised in my collections from these formations amounts to about one hundred and sixty or seventy, of which between thirty and forty are apparently new; but in the case of some of these the materials at present in my hands are not sufficient for description. Of this number no less than seventy-five belong to the corals, about forty are Braohiopods, and the remainder are distributed amongst the Polyzoa, Gasteropoda, Lamellibranchiata, Annelida, Trilobita, and Crinoidea.