On Conodonts from the Chazy and Cincinnati Group of the Cambro-Silurian, and from the Hamilton and Genesee-Shale Divisions of the Devonian, in Canada and the United States

Soon after the publication by Dr. Pander, in 1856, of his wellknown monograph, in which he announced the discovery, in the lowest fossiliferous rocks of Russia, of small ‘teeth” named Conodonts, and referred by him to fishes, several discussions arose as to the character of these minute bodies, and various opinions were expressed as to their near relations, without, however, any satisfactory conclusion being arrived at. Since that date Conodonts have been found in several other places; and in this communication I propose to describe a great variety of forms which I have collected within the last two years from several different formations in North America. Though my specimens may not suffice to determine the true position of the organisms to which they were attached, they will at least add something to our previous knowledge, and thus assist in reaching a decision on the subject. The next account, after Dr. Pander's, of the discovery of Conodonts is by Dr. J. Harley, in an article on the Ludlow bone-bed and its crustacean remains. Only two of the specimens described by this gentleman have any resemblance to the Conodonts of Pander; but a comparison of these with other very differently formed bodies in the same beds led him to express the opinion that all the forms were of crustacean origin, and that Conodonts were probably only spines similar to those attached to the margins of the carapace of Limulus and the caudal segment of Squilla. He therefore included all together under the provisional genus Astacoderma .