764 DR. .7. 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 the box containing the bones 

 in the same state in which they had been found, and handed them 

 over to me for description ou 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. Vertebrae ( 1 2 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, hut 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 fonta- 

 nelles, 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 ster- 

 num, has the close-grained reticulated surface which is so character- 

 istic 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 unfortu- 

 nately 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 dia- 

 meter 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 



