OCR Text |
Show 216 A few marine plants are found, but no land vegetation, except an occasional fragment of fossil wood. The absence of terrestrial plants is the more remarkable, as extinct birds and numerous amphibians indicate that dry land must have existed. One fine species of crinoid of a new genus was occasionally found by our party in 1875. No radiate had before been seen in the Kansas Cretaceous. Of raollusks, the most common are Ostrea congesta and Inoceramus problematicus. Less common, but still seen in many strata, are fragments of the large Haploscapha, with occasionally a perfect specimen. Another large bivalve we have never seen described measures from 30 to 33 inches in length. It is thin, with a transverse fiber like the Inocerami, and always lies crushed fiat in numerous fragments, but lying in their normal position. A few Oryphea; also fragments, frequently weighing ten pounds, of a large Hippurites near E. Toncasianus. Near Sheridan, we recently discovered a bed of Baculites ovatus. Almost all the shells and fragments are covered in part by the Ostrea congesta, which abound everywhere. But the great feature of this subdivision of the Cretaceous consists in its varied and rare forms of vertebrate fossils. Two seasons, of six months each ( 1874 and 1875), have been spent by myself with two assistants in collecting these vertebrates for Yale College, and yet the deposit is but partially explored, and we are constantly discovering new forms. The least interesting are the fish, which have, however, given us many new species and some new genera. The small ones are nearly entire, but the larger are represented only by well- preserved portions of the skeletons. Teeth of Salachians were quite common. At one locality over 400 were collected in an area of 30 inches, and apparently from the jaTS of one individual- a Ptyeodus- and all in excellent preservation. Professor Cope, in his " Cretaceous Vertebrata," has described thirty-six species, and some twenty others have quite recently been found. In 1872, only twenty- four species had been collected from Kansas. The most novel is a new genus ( three species), which had a snout appended to the skull, like the sword of the sword- fish, but conical in shape, composed of a compact bundle of fibers. In the largest species, this snout is about fifteen inches long and one and a half in diameter at the base. Professor Cope has a representation of a portion of the jaws in Plate XLVIII, figs. 3- 8, under the name of Erisicthe nitida. But, unfortunately, his specimen did not embrace the snout or much of the skull, so that a correct idea of the fish is hot obtained from his description. Professor Marsh has a dozen specimens, recently obtained by us, from which a more detailed description may be ma^ e. In individuals, the fish were quite numerously represented. In the . season of 1875, our party saw, according to my note- book, 1,207 specimens, without counting the teeth of sharks. Many of these, however, were so fragmentary that we did not collect them. The genera Por. thrus and Empo were most abundant. Several species of marine turtle have been obtained. One described by Cope, Protostega gigas, was 15 feet in the expanded flipper. The type is embryonic This is seen in the structure of the ribs, which are more free and detached from the dermal plates of the carapace than those now living. The other species were much smaller. Less in number but of more importance are the reptiles of the crocodile and Saurian type. My note- book shows 476 specimens seen by our party in 1875, of which one- half might be called good, and some of |