•520 BIE. W. K. PAKKER ON THE OSTEOLOGY OF THE KAGU. 



Porphyrio. The posterior sharp edges of the metatarsus seen in these birds have 

 scarcely any existence in that of the Kagu. As in these its congeners, the Kagu has 

 the outer lower condyle connected with the middle condyle by a bony bridge, so that 

 the considerable open space between these two, below, is di\ided into a fenestra and a 

 notch. The condyles themselves (PI. XCII. figs. 11 & 11 b) diifer in the Kagu from 

 those of its congeners; they are much more outspread (Reptilian) than in the PsopMa, 

 wliilst in Enrypyga they are more compressed than even in Porphyrio, equalling what is 

 seen in the Coot {FuUca atra), and approaching the condition of these parts in the 

 (irebes {Podiceps). The small free metatarsal (PI. XCI. fig. 1, i. m.t) is placed high 

 up, as in the congeners of the Kagu ; and the " hallux " ' is of moderate length. The rest 

 of the toes are slender, and rather long (PI. XCI. fig. 1), the middle toe (fZ. 3) being more 

 than an inch and a half shorter than the tarso-metatarse. In the Psophia the middle 

 toe is only half the length of the shank ; in Enrypyga the middle toe is nearly two-thii'ds 

 the length of the shank ; whilst in Porpliyrio it is a quarter of an inch longer than the 

 tarso-metatarse. 



These variations are worth mentioning because of their zoological value; morpho- 

 logically, however, they have much less import, as they relate mainly to the correlation 

 of each type to its surroundings in actual life. 



In summing up the affinities of the Kagu, I may say that my view of it is that it is a 

 generalized Crane, that it is nearer of kin to Eurypyga than to PsopMa — the latter 

 coming near to the Balearic Crane, whilst Eurypyga, like the Kagu, makes a very near 

 approach to the Night-Herons amongst the typical Ardeinse. The Kagu is related to the 

 Rails ; but so, indeed, are all the GruinsB ; and Professor Huxley has, with great sagacity, 

 put both these families into one gi'oup, and has called this group the " Geranomorphte " 

 (see Proc. Zool. Soc. 1867, p. 457). 



EXPLANATION OF PLATES XCI. .\nd XCII. 

 PLATE XCI. 



Fig. 1. Side view of skeleton. 



'o 



Fig. 2. Upper view of cervical vertebrae. 



Fig. 3. Side view of sternum and shoulder-girdle. 



' The hinder toe is evidently the true " hallux ; "' but in my former papers it was described as the second 

 (fl. 2), on the supposition that the spur of the Cock represented the innermost digit. 



