. Carnegie Institution of Washington publication. '^°^T°°|W%°. Fig 104. -Callothynchus callorhynchus. Dental plates and neighboring mouth parts of late embryo (about I 10 mm. long). After Schauinsland. 105.—Callorhynchus. Detail of middle ridge of mandibular dental plate of specimen slightly younger (about 95 mm. in length) than the preceding. The dental ridge is seen as a transparent object. After Schauinsland. Fig. 106.—Callorhynchus. Dental plates of " larva" measuring about 16 cm. After spec- imen in museum of Columbia University. "family" or in "generic"
. Carnegie Institution of Washington publication. '^°^T°°|W%°. Fig 104. -Callothynchus callorhynchus. Dental plates and neighboring mouth parts of late embryo (about I 10 mm. long). After Schauinsland. 105.—Callorhynchus. Detail of middle ridge of mandibular dental plate of specimen slightly younger (about 95 mm. in length) than the preceding. The dental ridge is seen as a transparent object. After Schauinsland. Fig. 106.—Callorhynchus. Dental plates of " larva" measuring about 16 cm. After spec- imen in museum of Columbia University. "family" or in "generic" form, soon to be remodeled or erased. Thus we find in Callorhynchus, according to the ffgures of Schauinsland, that these tritors do occur in later embryonic stages (fig. 105), although this author does not refer distinctly to the relation of dermal cusps to tritors in Chimaeroid plates. Following briefly the jn-oblem of the dentition of Chimseroids, we may again refer to the presence of numerous papillae in the mouth region of these forms. For, by analogies in other fishes, these structures ma}' well represent rudiments of discrete denticles. It is, therefore, of particular interest that in the case of Callorhynchus, where the dental plates are heaviest and largest, we find a corresponding increase in the size of the papilbe. For it may be suggested that papilhe which have become calcified either singly or in groups, have retained their dentitional (and ancient) trend in evolution, while those which remain soft have survived because they have undergone a change of function. The similarity in dental and non-dental structures is shown strikingly in the roof of the mouth of Callorhynchus (fig. 104), after Schauinsland. That shown in the roof of the mouth of Chimasra (plate ix, fig. 50''), although not. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustratio
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