^"''ic^is'^' ] '^ii^^'P'^^'DT, Skeleton of Kea Parrot (Nestor notahilis). 4I 



The condyles are separated by a smooth, well-marked valley or 

 intercondylar space. In each one, their outer peripheries are 

 elevated, especially in the case of the inner one, which at the same 

 time is more elongate than the fellow of the other side. Both 

 stand well out beyond the shaft posteriorly. 



Passing to the consideration of the fibula, we find the bone to 

 be short, stout, and straight ; while distally it is sharp-pointed, 

 and when articulated, as in life, passes but a couple of millimeters 

 below the fibular ridge on the tibiotarsus (fig. 16). On its outer 

 side, at the juncture of the middle and lower thirds, there is the 

 usual tubercle for the insertion of the tendon of the biceps muscle. 



Distally, as well as proximally, the extremities of the tarso- 

 metatarsiis are more or less compressed in the antero-posterior 

 direction. This bone has a remarkable morphology, but this feature 

 is still more evident in the tarsometatarsus of Ara chloroptera. 



In the " Kea " the summit of the bone is more or less flat, 

 though it presents the usual shallow excavations for the condyles 

 of the tarsometatarsus. The hypotarsus is short, and very broad 

 and thickened. It is once-pierced for the passage of tendons, 

 and twice deeply grooved in the same direction, the latter being 

 completed behind by dense ligament. 



The shaft is rounded from side to side in front, and notably flat 

 posteriorly. Just below the hypotarsus it is twice-pierced antero- 

 posteriorly by minute foramina. 



Laterally, for the upper third of the shaft internally, there is 

 a strong longitudinal ridge developed. 



At the distal end of the bone, the usual foramen for the passage 

 of the anterior tibial artery is large, and a distinct groove leads 

 into it from above on the anterior aspect of the shaft. 



To meet the requirements of the zygodactyle foot, the bi-g 

 distal trochleas of this bone are turned and twisted in such a manner 

 as to almost give this end of the bone a deformed appearance. 

 The addition of a rather large " accessory metatarsal " rather 

 enhances this appearance. This entire morphology and arrange- 

 ment, however, is perfectly natural, and requires but a brief study 

 to convince one of its marvellous adaptation to the various move- 

 ments of the basial joints of pes in life. 



From a study of the bones of the foot, as shown in fig. 16 of 

 Plate X., it will be appreciated that not only are they arranged 

 for the four toes upon the more usual plan of 2, 3, 4, 5 joints for 

 the first, second, third, and fourth toes respectively, but that all 

 these joints are unusually large and strong, with very complete 

 and extensive interarticulations. As we would naturally expect 

 in this notable carnivorous member of the Psittacine assemblage, 

 the ungual joints are each sheathed in a big, strong, and curved 

 podothecal sheath, the distal end of each being quite as sharp- 

 pointed as we find it to be in not a few Falcons ; indeed, Nestor 

 possesses on a whole a foot that might well grace the pelvic limb 

 of any average Falconine bird, or even that of some big Owl. 



