. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 208 ANNALS OF THE SOUTH AFRICAN MUSEUM near the junction of the fore- and mid-brain. From fossil material it is impossible to say which of these structures—epiphysis, paraphysis, pineal organ or parietal organ—were present in life or what part of the parietal canal was occupied by each component part of what we have to call the 'parietal' organ. The large volume of the parietal organ in the Dinocephalia is unique. Part of the material may have been glandular as is the pineal gland of mammals which se
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 208 ANNALS OF THE SOUTH AFRICAN MUSEUM near the junction of the fore- and mid-brain. From fossil material it is impossible to say which of these structures—epiphysis, paraphysis, pineal organ or parietal organ—were present in life or what part of the parietal canal was occupied by each component part of what we have to call the 'parietal' organ. The large volume of the parietal organ in the Dinocephalia is unique. Part of the material may have been glandular as is the pineal gland of mammals which secretes internally. Part of the mass was certainly nervous with a receptor function either visual or thermal or both. By analogy with living forms a thermo-regulatory function is probable. The optic lobe of the midbrain would lie posterior to the emergence of the Ilnd nerve. The flocculus can be determined as a slight bulge just posterior to the trigeminal fenestra and above the vestibule. The IXth, Xth, and Xlth nerves leave the medulla low down, but the Xllth emerges somewhat higher up from the lateral face of the medulla. The basicranial axis (Fig. 8) In figure 8A the bones of the basicranial axis are shown in relation to the occipital and the otic bones and the pterygoid of the palatoquadrate as exposed in ventral view. It is thus evident that the parasphenoidal rostrum is directed obliquely upwards so that the pterygoids meet below it, but its tip can be seen through the interpterygoid vacuity. The pterygoid has a long suture with the parabasisphenoid reducing the original joint between the palatoquadrate and. Fig. 8. Stmthiocephalus whaitsi 12049 X £. The basicranial axis as reconstructed. A. Ventral view in relation to supporting bones. B. Ventral view. C. Lateral 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
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
