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Show 764 DR. J. HECTOR ON CNEMIORNIS CALCITRANS. | Dec. 2, and the thickness of the bony wall found to be so great that the internal diameter is only two thirds that of the external. In consequence of the divergence of character from the humerus described by Professor Owen, I was much interested in obtaining the remainder of the bones of this skeleton ; and after tracing it through several hands, Captain Fraser at last succeeded, only a few weeks ago, in obtaining possession of tbe box containing the bones in the same state in which they had been found, and handed them over to me for description on the 20th ultimo. The skeleton is still far from complete; but the following bones are in a very admirable state of preservation, and agree perfectly in appearance, colour, peculiar stains, texture, and other external characters; so that there is no reason to doubt that they all belong to one individual, which is further confirmed by the study of their anatomical characters:- 1. Skull. 7. Sacrum. 2. Vertebrse (12 cervical, 4 dorsal). 8. Femur. 3. Sternum. 9. Tibia. 4. Furcula. 10. Tarso-metatarsal. 5. Humerus. 11. Ribs (6). 6. Carpal. The structure and form of the skull and sternum show that this bird belongs to the Lamellirostrate Natatores, but that the power of flight had become obsolete, and that it differs from most others of the duck-kind in its short lofty head, very solid palate, and in the peculiar character of the tympanic cavity, which is bridged across by a bony process between the mastoid process and the basioccipital. The great solidity of the skull, and the absence of occipital fontanelles, and the free sutures of the naso-frontal and the lachrymal bones are also remarkable. Every bone of the skeleton, excepting the upper part of the sternum, has the close-grained reticulated surface which is so characteristic of the bones of Cnemiornis, giving the impression of a very solid powerful framework that in the fresh state would contain much oily matter; and the absence of the power of flight is evidenced by the rudimentary tubercular ridge that represents the keel, and the small area included by the pectoral ridges on the surface of the sternum. Skull. (Plates LXVI. and LXVII.) What remains of the skull is well preserved, every process being sharp and distinct as in a freshly macerated specimen; but unfortunately the following appendages have been lost:-the quadrate, jugal, pterygoid, and lachrymal bones. The head, including the lower jaw, and allowing the usual proportion for the quadrate, would have the height equal to two thirds the length, and the transverse diameter equal to half the length. The brain-case is short, high, and compressed laterally, its postero-inferior diameter being greatest. The nasal portion of the skull, which is distinctly shorter than the cranial, is detached; and the |