. The Bashford Dean memorial volume : archaic fishes. Fishes; Sharks; Fishes, Fossil. 194 Bashford Dean Memorial Voluyne head roof by a solid wall (Text-figure 13 CR). Thus the neurocranium could hardly continue into them. A careful study of the head roof of Dinichthys led Stetson (1930) to give another picture of its neurocranium (Text-figure 82A). He conjectured that the neurocranium occupied the central thinner part ot the head roof and was clearly limited by the lateral. AMV Text-figure 83. Longitudinal section of the head and body armor in Dinichthys showing the position of the neurocrani
. The Bashford Dean memorial volume : archaic fishes. Fishes; Sharks; Fishes, Fossil. 194 Bashford Dean Memorial Voluyne head roof by a solid wall (Text-figure 13 CR). Thus the neurocranium could hardly continue into them. A careful study of the head roof of Dinichthys led Stetson (1930) to give another picture of its neurocranium (Text-figure 82A). He conjectured that the neurocranium occupied the central thinner part ot the head roof and was clearly limited by the lateral. AMV Text-figure 83. Longitudinal section of the head and body armor in Dinichthys showing the position of the neurocranium (hned and cross-hatched) and of the gnathal muscles (lined and numbered). Mc, nasal capsule; ?{p. neurocranial process; fm, foramen magnum; /, II, I//, IV, gnathal muscles. Outline of spinal column schematic. head thickening (LCP). Like Woodward, Stetson thought that the thickened central part of C is a separate plate, but one not limiting the hind part of the brain-case (Text- figure 82A x-x). The hind part of the neurocranium was narrow and was placed along the median line of MB. Into the deep bilobed impression on the hind part of MB (Text- figure 13 ds) fitted the "cranio-spinal process," which was developed in Dinichthys as in Macropetalichthys. Stetson states that the impressions for the ''musculi depressores capitis" were probably "cavities for branchial apparatus" (Text-figure 82A y-)i). As mentioned before, I cannot accept the relationship between Macropetalichthys and the Arthrodira, and therefore believe that the Arthrodira never possessed the "cranio- spinal ; The bilobed depression on A^ is the attachment place for the musculi levatores capitis. When trying to reconstruct the position and size of the neurocranium in Dinichthys, we must first find some definite points, which, for certain, have been in contact with the. Please note that these images are extracted from scanned page images that may have been digitally enhan
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