. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. Text'figure 7- Three different views of a tooth of Chlamydoselachus, six times natural size: A, seen from above; B, from the side; C, from beneath. After Garman, , Figs. 1, 3 and 4, pi. VI. The essential similarity of the internal structure in scales and teeth of sharks is evident from a comparison of Text-figure 8 with Text-figure 9. Each has the form of a hollow cone, slightly recurved at the apex. Each is composed of dentine (D., ) overlaid with enamel (e., S.). The dentine is traversed by canals (d. c.) radiati
. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. Text'figure 7- Three different views of a tooth of Chlamydoselachus, six times natural size: A, seen from above; B, from the side; C, from beneath. After Garman, , Figs. 1, 3 and 4, pi. VI. The essential similarity of the internal structure in scales and teeth of sharks is evident from a comparison of Text-figure 8 with Text-figure 9. Each has the form of a hollow cone, slightly recurved at the apex. Each is composed of dentine (D., ) overlaid with enamel (e., S.). The dentine is traversed by canals (d. c.) radiating from the pulp cavity (p. c. and P.). Both scales and teeth are exoskeletal structures. Evidently teeth, which are the more complex, have developed from the same materials and in the same manner as scales. It would, perhaps, be a trifle crude to say that teeth are developed from scales, but it seems entirely proper to say that teeth are homologous with scales. This has long been admitted, but in Chlamydoselachus we have material exceptionally favorable for revealing the precise manner in which teeth correspond to scales. Superficially, the chief difference. 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 Dean, Bashford, 1867-1928; Gudger, E. W. (Eugene Willis), 1866-1956. New York : [American Museum of Natural History],
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