^"'-^iV'] ^KVFE'LVT, Skeleton of Kea Parrot {Nestor noiahilis). 35 



neural spines intimately articulated throughout the series ; 

 indeed, in the case of the first and second dorsal vertebrae no 

 opening occurs between them. Only the first and second dorsals 

 possess rather short haemal spines, the ultimate one being slightly 

 bifid. These characters, as seen upon dorsal aspect, are well 

 shown in fig. 15 of the present contribution, especially the broad 

 transverse processes, which, on either side, supports a single, 

 backward-proj ecting metapophysis. 



All the vertebrae of the spinal column, with the possible excep- 

 tion of the last few caudals and the pygostyle, are thoroughly 

 pneumatic ; this also applies to both the thoracic and the costal 

 ribs. 



Nestor has its ribs very perfectly developed, the entire series 

 being, as a whole, a most efficient protection to the contained 

 organs and structures of the thorax and anterior abdominal cavity. 



There are four pairs of dorsal ribs and two pairs of pelvic ones ; 

 they all connect with the sternum by the intervention of costal 

 ribs, their modes of articulation being as they occur in all ordinary 

 birds (ligs. 13, 14, and 15 of the plates). 



Large epipleural appendages occur on the first four pairs of 

 these dorsal thoracic ribs ; and, upon either side, each overlaps 

 the next rib following it. Curiously enough, on the last thoracic 

 rib of the left side, there are two small epipleural appendages, the 

 smaller one of the pair being the lowermost one (fig. 13). There 

 are no epipleural appendages on the corresponding rib of the 

 right side. No case similar to this has ever been seen by me in 

 any bird, in so far as I can remember at the present time. 



As we pass from before, backwards, the distal ends of the sternal 

 ribs become more and more expanded. It is hardly noticeable 

 in the first pair, but a decided feature of the ultimate pair. On 

 the right side this latter bone has a short, very narrow, super- 

 numerary sternal rib articulated with its distal posterior margin. 

 Such vestigial osseous structures are interesting, and may point 

 to the fact that the early ancestors of Nestor possessed more ribs 

 than this existing form of the species. This supernumerary costal 

 rib is well shown in fig. 14 of Plate VIIL — in fact, close inspection 

 of figs. 13 and 15 will likewise reveal both of these anomalies. 



The ultimate two pairs of thoracic ribs of Nestor articulate with 

 the pelvis, and so are pelvic ribs ; they are not followed by any 

 rudimentary ones more posteriorly, as so often happens among 

 birds of other families. 



Other Parrots have two pairs of pelvic ribs, as, for example, 

 Amazona leucocephala and its near allies. 



Nestor has five free caudal vertebra in its tail skeleton. Morpho- 

 logically, they are very much alike, while they vary but little in 

 the matter of size. Each has a stumpy, blunt neural, spine and 

 the last two haemal spines, the one in the fourth being very rudi- 

 mentary, while the ultimate one is much better developed and 

 anteriorly bifid. All these vertebrae have stout diapophyses that 

 are directed downwards and outwards (figs. 13, 14, and 15). 



