. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. The Embryology of Heterodontus japonicus 697. Text-figure 29. Teeth of Hybodus, outer aspect, natu- ral size: A, three associated teeth of Hybodus delahechei Charlesworth; B, three associated anterior teeth of Hybodus reticulatus Agassiz. After Woodward, 1889, Part 1, pi. X. in some larger group; but we are here concerned mainly with the interrelations of the two families. From this point of view, the descriptions of the teeth by Woodward are inadequate when isolated from the special accounts of the teeth of the various gen
. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. The Embryology of Heterodontus japonicus 697. Text-figure 29. Teeth of Hybodus, outer aspect, natu- ral size: A, three associated teeth of Hybodus delahechei Charlesworth; B, three associated anterior teeth of Hybodus reticulatus Agassiz. After Woodward, 1889, Part 1, pi. X. in some larger group; but we are here concerned mainly with the interrelations of the two families. From this point of view, the descriptions of the teeth by Woodward are inadequate when isolated from the special accounts of the teeth of the various genera. There is considerable variation in the teeth of different genera in both families, and the differences are of the same kind. In Hybodus the teeth (Text-figures 29 and 30) are all cuspidate. In the anterior teeth the cusps are more or less acute, with the central cusp predominant and the other cusps somewhat irregular in sizie and number. In the posterior teeth there is a tendency toward differentiation into grinders; for these teeth are larger than the anterior teeth and their cusps are almost or quite obtuse. But in some other genera of the family Hybodontidae, low rounded crushing teeth, slightly ridged and with only a few vestigial cusps, occur (, as in Orodus, figured by Eastman, 1903; and Acrodus, beautifully illustrated by Woodward, 1889). Similar differences occur in the three genera of the Cestraciontidae. The teeth of Synechodus (Text-figure 31) are much like those of Hybodus (Text-figures 29 and 30). 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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