. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. DENISON: THE CYATHASPIDIDAE 351 that have smooth or gently scalloped edges. The chambers of the cancellous layer are usually large and separated by more or less ver- tical septae. The lateral lines are canals in the cancellous layer that open to the surface by pores; they are arranged in a simple pattern consisting of two pairs of longitudinal canals dorsally and ventrally, transverse commissures, infraorbital, and supraorbital, and perhaps profundus lines. Fig. 107. dorsal shield 1932.) orb, orbit. To
. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. DENISON: THE CYATHASPIDIDAE 351 that have smooth or gently scalloped edges. The chambers of the cancellous layer are usually large and separated by more or less ver- tical septae. The lateral lines are canals in the cancellous layer that open to the surface by pores; they are arranged in a simple pattern consisting of two pairs of longitudinal canals dorsally and ventrally, transverse commissures, infraorbital, and supraorbital, and perhaps profundus lines. Fig. 107. dorsal shield 1932.) orb, orbit. Tolypelepis undulata, (X 2). (From Kiaer,. Tolypelepidinae The dorsal shield appears to be composed in part of fused scales, and is divided into distinct epitega. Most dentine ridges are short, and the central ridges of the scale components are broader and higher than the surrounding ridges. The central ridge pattern is elliptical, the rostral pattern is transverse, and a postrostral field may be dis- tinguished. Tolypelepis. Tolypelepis Pander Type-species.—Tolypelepis undulatus Pander. Tolypelepis Pander, 1856, Mon. foss. Fische Sil. Syst. Gouvern., pp. 60-61; Lindstrom, 1895, Bihang K. Svensk. Handl., 21, Afd. 4, Nr. 3, p. 10; Strand, 1934, Folia Zool. Hydrobiol., 5, pp. 327- 328; Flower and Wayland-Smith, 1952, Bull. Mus. Comp. Zool., 107, p. 370; Denison, 1953, Fieldiana: Geol., 11, no. 7 p. 293; Bystrow, 1955,. 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 Denison, Robert H. (Robert Howland), 1911-1985; Chicago Natural History Museum. Chicago : Chicago Natural History Museum Press
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