. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. cc2 dr- Fig. 103. A, oblique section through superficial, reticular and cancellous layers of dermal shield of Irregulareaspis sp., CNHM, slide 4590 (X 25); B, tan- gential section through superficial layer of Anglaspis sp. (from Gross, 1961) (X 50). ca, chamber of cancellous layer; cch longitudinal canal connecting pulp cham- bers; cci, canal connecting pulp chamber to intercostal groove; cc:i, canal connect- ing pulp chambers of adjacent dentine ridges; dr, dentine ridge; ig, intercostal groove; pc, p
. The Cyathaspididae; a family of Silurian and Devonian jawless vertebrates. Cyathaspididae. cc2 dr- Fig. 103. A, oblique section through superficial, reticular and cancellous layers of dermal shield of Irregulareaspis sp., CNHM, slide 4590 (X 25); B, tan- gential section through superficial layer of Anglaspis sp. (from Gross, 1961) (X 50). ca, chamber of cancellous layer; cch longitudinal canal connecting pulp cham- bers; cci, canal connecting pulp chamber to intercostal groove; cc:i, canal connect- ing pulp chambers of adjacent dentine ridges; dr, dentine ridge; ig, intercostal groove; pc, pulp chamber; sc, lateral line sensory canal. The outstanding feature of the reticular layer is its numerous canals which bring vascular and nervous supply to the superficial structures. These canals are: (1) Pulp canals of the dentine ridges (figs. 100-103, pc); when these canals are paired, as in Allocryptaspis (fig. 104,A) and Sanidaspis, there are numerous cross connections between the members of a pair; or where the pulp canals are divided into chambers, as in Tolypelepis and Anglaspis, there are longitudinal canals (fig. 103,B, cc\) connecting the chambers. (2) Canals lateral from pulp canals to the intercostal grooves; these are abundant and regular in Poraspis (fig. 102,A), Americaspis (fig. 102,B, cc2), and Sanidaspis; they emerge from each of the pulp chambers of Anglaspis (fig. 103,B, cc2); they are relatively few in number in Allocryptaspis (fig. 102,C, cc2). (3) Canals passing laterally from the pulp canals and continuing under the intercostal grooves; in Anglaspis (fig. 103,B, ccs) they may connect directly with the pulp canal of the neighboring ridge; in Allocryptaspis they meet vertical or oblique canals leading from the cancellous layer to intercostal 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
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