Page:Quarterly Journal of the Geological Society of London, vol. 35.djvu/423

 AND DEVONIAN CONODONTS. 353 pyrites. In addition to the Conodonts, there are in this same bed numerous fragments of Crinoid stems, bones and plates of undeter- mined fishes, and teeth closely resembling, if not identical with, those of Ptyctodus *, Pander, also from Devonian strata in Russia ; but there are no remains of Crustaceans or Gasteropods. It is only on the weathered surface of the rock that Conodont teeth are visible, and then only with the assistance of a good lens. There are also a few Conodonts associated with plates and teeth of fishes in a thin band of limestone of the Hamilton group at Arkona, Lambton County, Ontario. Immediately succeeding the Hamilton group are beds of black bituminous shale, known as the Genesee Shale in New York and Canada, and as the Huron Shale in Ohio ; and the Conodonts are distributed in these shales, in places widely apart. I have found them in exposures of these strata at Kettle Point, on the shores of Lake Huron, and at Bear Creek, both in Lambton County, Ontario, as well as in small boulders derived from these beds in the cliff- sections on the north shore of Lake Erie : at North Evans, New York, where there is a splendid section of these shales, Conodonts are also abundant ; and I have also fragments from the same shales near Louisville, in Kentucky. At all these localities these shales are but sparsely fossiliferous, and the fossils are limited to spores of Lycopods and portions of other plants, a few Brachiopods of the genera Lingula and Distinct, Aviculce, and the scales, mostly de- tached, of Palceoniscus. There are no organic fragments to give any clue to the animal to which these numerous Conodont teeth belonged. Though my paper does not include the Lower Carboniferous Cono- donts of Ohio, treated by Dr. Newberry, I may mention, from my own examination of the beds in which they occur, that the strata are black shales not dissimilar in appearance to the Genesee shales, but less bituminous ; and, like these latter also, have scarcely any other organisms in addition to the Conodonts but plants and scales of Ganoid fishes. My object in mentioning somewhat in detail the fossils occurring with the Conodonts in the different formations has been to point out that they cannot be attributed to these associated organisms, and to show the probability, so far as negative evidence extends, that these minute teeth and plates are the only portions of the animals capable of preservation in a fossil condition. The appearance of the American Conodonts is so similar to those from Russia that Pander's description will almost equally apply to both. They occur as very minute, shining bodies, sometimes con- sisting of a single more or less curved conical tooth with an ex- panded base ; but more frequently they possess an elongated basal portion in which there is generally a large tooth with rows of similar but smaller denticles on one or both sides of the larger tooth, accord- ing as this is central or at one end of the base. In some forms the p. 40, table 8. 2o2
 * ' Ueber die Ctcnocliptcrincn des devoniscken Systems,' St. Petersburg, 1858,