Report of the Annual Meeting Volume 18

Report of the Annual Meeting Volume 18

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1849 edition. Excerpt: ...dental structure, which corresponds with that of the posterior teeth in Alligators, --the articulation of the neurapophyses to the bodies of the vertebrae, --the complicated pectoral arch, --the sternum and complete abdominal cincture of ribs, &c. The circle of numerous imbricated sclerotic bones reaches its maximum of development in the Ichthyosaurus; but this is an exaggeration of a structure feebly shadowed forth in some existing Saurians, and more strongly shown in Birds, rather than a repetition of the simple bony sclerotic cup in Fishes. By no known forms of fossil animals can we diminish the wide interval which divides the most sauroid of Fishes from an Ichthyosaurus. This most extraordinary Reptile is a singular compound in which Ichthyic, Cetacean, and Ornithic characters are engrafted upon an essentially Saurian type of structure. The Ichthyosaurus is, therefore, just such a form of animal as might be expected, were specific forms unstable, to demonstrate a mutation of characters or some tendency towards a progressive development into a higher and more consistent type of organization. Nor is the field for testing the transmutation theory less ample than the subject is favourable. We have the opportunity of tracing the Ichthyosauri, generation after generation, through the whole of the immense series of strata which intervene between the new red sandstone and the tertiary deposits. Not only, however, is the generic type strictly adhered to, but the very species, which made its first abrupt appearance in the lowest of the qolitic series, maintains its characters unchanged and recognizable in the highest of the secondary strata. Jn the chalk formations, for example, the genus Ichthyosaurus quits the stage of existence This...show more

Product details

  • Paperback | 272 pages
  • 189 x 246 x 14mm | 490g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236766075
  • 9781236766076