Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/101

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1869.]
HUXLEY—DINOSAURIA AND BIRDS.
15

oval bone was called a coracoid. I pointed to an incomplete bone which you quickly decided to be humeral—rather a small bone as compared with the femur.

"Turning now to the hinder extremity, it was easy to see that as the small glenoid cavity formed in the scapular and coracoidian bone was fitted for a small humerus, so the great hollow in the heavy, arched pelvic bone was adapted to the large head of the well-known femur, 3 feet long. But to name this great pelvic bone was a difficulty with me. I was under the impression that its broad, smoothly expanded surface might be best compared with that of an ischium[1] or pubis, and that this would be more suited to the broad depressed body (as I supposed it to be) of such a huge creature, than, by accepting it as an ilium, to admit the beast to have been narrow in the rear, like a bird, with the plane of the bone not much inclined from the vertical. The only points in favour of its being possibly an ilium were, first, its resemblance to that bone in birds, and specially in Apteryx (to which I confess I gave but little importance, as too unlikely to be accepted), and, secondly, marks apparently of bony attachment, on one face of the bone, such as might be left by the removal of cohering processes from the sacrum. To this I was reluctant to give weight for the same reason, viz. that it seemed to make Megalosaurus too 'sib' with primæval birds. In this state of mind you found me, and, to my surprise, took up de novo, and resolutely, to compare the bone with the pelvic arrangement of Ostrich and its congeners[2]. You also then seized upon the so-called "clavicle," and rapidly placed it in a probable manner to one of the tuberosities which project beyond the acetabular cavity, and called it an ischial or else a pubic bone, of struthious rather than lacertian analogy. Every observation which I have since been able to make goes to confirm this result, and the corollary from it, viz. a decided ornithic alliance of the pelvic, as we already found in the sternal, arrangement. Perhaps in the same direction may be cited the distinctly tubular character of the limb bones, which I have not perceived as yet in Cetiosaurus, though it may perhaps be found to be the case, and I think it will be.

"As you are now engaged in working out the true affinities of this uncommon creature, I propose to send you careful drawings of our most characteristic specimens, and will now only request your attention to one or two things which have occurred to my observation.

"These are two forms of the great pelvic (ilial) bone—the well--

  1. In his "Report on British Reptiles" (British Association Reports, vol. i. p. 109), Prof. Owen describes "a subcompressed three-sided bone, flattened and slightly expanded at one end, thickened and more suddenly extended transversely at the opposite end, which formed part of a large cotyloid cavity," as most likely an ischium. "Length 18 inches, breadth at the middle of the shaft 5 inches, at its articular end 9 inches, the thickness of this end 4 inches." Where is this bone preserved?
  2. It appears that Buckland had suggested to Cuvier, but unsuccessfully, what now appears to be the right view; for we read, "Toutefois je ne puis guère douter que ce ne soit un coracoïdien de Saurien: il ressemble beaucoup moins à leur os des îles, auquel M. Buckland l'a comparé" (Oss. Foss. v. pl. 2, p. 346).