. The Bashford Dean memorial volume : archaic fishes. Fishes; Sharks; Fishes, Fossil. TEETH OF CHLAMTDOSELACHUS The fang'like teeth are arranged in rows extending obliquely from front to back across each jaw, as may be seen in Figures 8,9, and 10, plate III; also in Figures 11—14, plate IV; and lastly in Figure 15, plate V. A single row of teeth, about times the natural si2;e, is portrayed in both dorsal and ventral aspects in Text'figure 9. These are enlarge- ments of the teeth found in Giinther's drawing (Figure 1, plate I). They have been retouched by our artist to make them sharp and c
. The Bashford Dean memorial volume : archaic fishes. Fishes; Sharks; Fishes, Fossil. TEETH OF CHLAMTDOSELACHUS The fang'like teeth are arranged in rows extending obliquely from front to back across each jaw, as may be seen in Figures 8,9, and 10, plate III; also in Figures 11—14, plate IV; and lastly in Figure 15, plate V. A single row of teeth, about times the natural si2;e, is portrayed in both dorsal and ventral aspects in Text'figure 9. These are enlarge- ments of the teeth found in Giinther's drawing (Figure 1, plate I). They have been retouched by our artist to make them sharp and clear'cut. The single teeth have been enlarged about times. The rows are separated by toothless spaces, which are in width about equal to the width of the adjacent rows of teeth. Posteriorly the spaces become narrower, and at about the seventh or eighth row of teeth, the toothless spaces become very much reduced and the rows of teeth are so closely set that it is difficult to distinguish the rows. The teeth in these posterior rows are very small and are rudimentary in structure. In the symphysis of the lower jaw there is a median row of teeth. At the point of each jaw the outermost teeth of each row are bent so far out beyond the margin of the jaw that they are on the exterior when the mouth is closed. This is particularly true of the lower jaw. For all these points see Plate III, figures 8, 9 and 10. In their form the teeth are unlike those found in any other existing shark. Each tooth has three slender, curved, inwardly directed cusps or den- ticles set on a broad base (Text-figure 10) which projects behind and interlocks with the base of the tooth posterior to it, so that it cannot ordinarily be overturned by an outward pull. There are a central and two lateral cusps of approximately the same sizje, and between the central and each lateral cusp is a rudimentary cusp or denticle. For these details of the structure of the teeth of Chlamydoselachus see our Text-figure 10 w
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