. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. Text-figure 6. Three different views of a placoid scale or dermal denticle (x 130) from a 340-mm. embryo of Chlamy- doselachus: A, scale from the flank, viewed from above; B, lateral view of a scale from the region of the tail; C, scale from the region of the tail, seen from beneath. After Rose, 1895, Abb. 1, 2, 3. accessory spines. Of the atypical scales, those forming the "armature" on the anterior edge of the dorsal fin (Garman, , p. 7; Gudger and Smith, 1933, p. 294) are interest- ing because, in form an
. The Bashford Dean memorial volume :. Fishes; Sharks; Fishes, Fossil. Text-figure 6. Three different views of a placoid scale or dermal denticle (x 130) from a 340-mm. embryo of Chlamy- doselachus: A, scale from the flank, viewed from above; B, lateral view of a scale from the region of the tail; C, scale from the region of the tail, seen from beneath. After Rose, 1895, Abb. 1, 2, 3. accessory spines. Of the atypical scales, those forming the "armature" on the anterior edge of the dorsal fin (Garman, , p. 7; Gudger and Smith, 1933, p. 294) are interest- ing because, in form and arrangement, they resemble the "fulcral scales" of the Actin- opterygii. The latter are described by Goodrich (1909, p. 304), and are said to be quite peculiar to this group. A typical tooth, viewed from three aspects, is represented in Text-figure 7- It has three sharp, slender, curved cusps, and two rudimentary cusps or denticles. It is attached to the jaw in such fashion that the denticles project inward toward the mouth cavity. The broad base of the tooth is prolonged posteriorly (toward the interior of the mouth) and is forked so as to interlock with a paired excavation in the base of the suc- ceeding tooth. In the illustrations the prongs of the base might readily be mistaken for cusps, but in the actual specimens the appearance is very different since the base is com- posed entirely of dentine while the cusps are covered with shiny white enamel,. 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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Keywords: ., book, bookcentury1900, booksubjectfishes, booksubjectfishesfossil
