The skeleton in the flying lemurs, Galeopteridae / by R.W. Shufeldt.

  • Robert Wilson Shufeldt
Date:
1911
Catalogue details

Licence: In copyright

Credit: The skeleton in the flying lemurs, Galeopteridae / by R.W. Shufeldt. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    from tree to tree, through great distances. When at rest, the Oaleopifheci suspend themselves by their fore- and hind-feet, the body and the head hanging downward! a position wdiich is sometimes assumed by the Marmosets among tlie Primates” Selecting from this account only such parts as refer to the skeleton, we note that Huxley observed that in Cynocephahis “the fore-limbs are slightly larger than the hind-limbs” and further that “the pollex and the hallux are short, and capable of considerable movement in adduction and abduction, but they are not opposable; and their claw's are like those of the other digits. “The occipital foramen is in the posterior face of the skull. The orbit is nearly, but not quite, encircled by bone. The lachrymal foramen is in the orbit. The bony roof of the palate is wide and its posterior margin is thickened. There is a strong curved post-glenoidal process of tlie squamosal, which unites with the mastoid, beneath the auditoiy meatus, and restricts the movement of the mandible to the vertical plane. A longitudinal section of the skull shows a large olfactory chamber projecting beyond that for the cerebral lobes, and two longi- tudinal ridges, upon the inner face of the latter, prove that these lobes must have possessed corresponding sulci. The tentorial plane is nearly vertical and the floccular fossae are very deep.” All these points are characteristic and cor- rectly stated. “The ulna” he adds, “is very slender interiorly, where it becomes anchylosed to the distal end of the radius, [?] which bears the carpus. When the ilia are horizontal, the acetabula look a little upward and backward as well as outward. The fibula is complete. As in the Sloths and most Primates, the navicular and cuboid readily rotate upon the astragulus and calcaneum so that the planta pedis is habitually turned inward.” In giving the dental formula, Huxley also refers to the peculiar pectination of the lower, single-fanged, incisor teeth, but these structures will be touched upon later on. Passing to the work of another writer who has investigated the anatomy of the family Galeopteridas we find that Flower points out a number of the characters of the skeleton in these “aberrant Insectivores,” ® now being examined. Briefly, he says : The characters of the family are those of the suborder Dermoptera, to which may be added that the orbit is nearly surrounded by bone, the zygomatic arches are well developed, the tympanies fonii bullae ossese, the ulna is distally united with the radius, the tibia and fibula are distinct, the pubic symphysis is long. Then follow descrijrtions of other parts of structure of these animals. Flower, it is observed, agrees with Huxley with respect to the ankylosis of the bones of the forearm, but that is one of the points that the present paper will settle. From another work® by the same author we learn that in Cynocephalus “each vertebra bears at its hinder end a pair of hypopophysial tubercles;” that the number of trunk vertebrae is 21 (15 thoracic and 6 lumbar); that the tail is 'The Anatomy of Vertebrated Animals (1872), 382, 383. ’Osteology of the Mammalia in Encyclopedia Britannica. 9th ed.. 15, 401. ’ Osteology of the Mammalia, 39.