. Report of the Geological Survey of Ohio. Geology; Paleontology; Mines and mineral resources; Zoology; Paleobotany; Botany. Front and side views of head, natural size, drawn from specimen. From these figures it will be'seen that the dentition of Lepidosiren con- sists of mandibles which have almost the exact form of those of Dinich- thys TerrelU, and have the same structure and functions. In Lepidosiren the anterior extremity of each mandible rises into a prominent tooth, while, behind this, the upper margin presents, first, a ridge or fold, which produces a subordinate denticle, and then, fo
. Report of the Geological Survey of Ohio. Geology; Paleontology; Mines and mineral resources; Zoology; Paleobotany; Botany. Front and side views of head, natural size, drawn from specimen. From these figures it will be'seen that the dentition of Lepidosiren con- sists of mandibles which have almost the exact form of those of Dinich- thys TerrelU, and have the same structure and functions. In Lepidosiren the anterior extremity of each mandible rises into a prominent tooth, while, behind this, the upper margin presents, first, a ridge or fold, which produces a subordinate denticle, and then, for about one-third the length of the mandible, is a sharp edge of enamel. At its posterior end this is slightly denticulated, as though with rudimentary teeth, as in Dinichthys. In the upper jaw we find two dfental plates, more or less perfectly joined at the symphysis, and forming, first, by a strong anterior fold on either side, prominences which are functional teeth, and which match the pro- duced extremities of the mandibles. Behind these, on each side, is a second ridge or fold, and then a wing-like plate of enameled bone, which plays upon the corresponding edge of the mandible. The most cursory examination of the figures and descriptions of the dentition of Dinich- thys will show that it corresponds closely to this pattern. In Lepidosiren there are also two small, pointed teeth (" nasal," Owen • " vomerine," Huxley) which overhang and precede the dentition that has been described. JSTo teeth corresponding to these have been discovered with the remains of Dinichthys, but this is not strange, for even if the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Geological Survey of Ohio. Columbus, Nevins & Myers, state printers
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