OCR Text |
Show 54 PROF. W. B. BENHAM ON THE OSTEOLOGY [Feb. 4, careful examination of the posterior half of the atlas shows that it is not perfectly symmetrical. The sixth vertebra is distinctly asymmetrical, but the seventh has retained its normal symmetry. The drawing exhibited (text-fig. 9, p. 53) illustrates the facts that have been dealt with. Dr. Chalmers Mitchell, F.Z.S., read, on behalf of Mr. E. Degen, a paper entitled " Ecdysis, as Morphological Evidence of the original Tetradactyle Feathering of the Bird's Fore-limb, based specially on the Perennial Moult of Gymnorhina tibicen." The material on which the paper was based consisted of a large series of specimens of the Gymnorhina obtained at regular intervals throughout the moulting-period, and the author had thus been able to give a very complete account of the perennial replacement of the feathers, avoiding the errors due to observations on the altered habits as produced by captivity. The author showed that the moulting of the wing-feathers took place in definite groups, and indicated a composite origin of the modern feathering. He thought that the new facts brought forward strengthened his already published theory of the wing-feathers being derived from the feathers of a four-fingered manus. Incidentally he suggested that the eutaxy of the Passeres was essentially different from that of such primitive birds as the Gallinae. This Memoir will be published in full in the Society's ' Transactions.' The following papers were read :- 1. Notes on the Osteology of the Short-nosed Sperm-Whale. By W. BLAXLAND BENHAM, D.SC, M.A., F.Z.S., Professor of Biology in the University of Otago, New Zealand. [Received November 8, 1901.] (Plates II.-IV.1) A specimen of the Short-nosed Sperm-Whale (Cogia breviceps) came into m y possession in 1900, and I have already communicated to the Society some remarks on certain of the viscera2. I now wish to offer some notes on the skeleton. The animal, a male measuring 8 ft. 9 inches, had been cast ashore on the sandy beach at -Parakanui, Otago; and though it had been a good deal cut about, I was able to obtain the entire skeleton, together with the cartilaginous portions of such structures as the hyoid, sternum, and limbs : these were put through the gelatino-glycerine process without any previous separation from the bones 1 For explanation of the Plates, see p. 62. 2 See P. Z. S. 1901, vol. ii. p. 107. |