Mr. W. K. Parker on the Kagu. 385 
short way up the centre of the nape. The front claws are short and 
acute. 
It differs from the Zorilla Vaillantii, Loche (Rev. et Mag. de Zool. 
1856, viii. 497, t. 22), in the crown of the head being entirely white, 
and the streak on the back narrower and well-defined. 
On THE OsTEoLocy or THE Kacu (RHINOCHETUS JUBATUS). 
By W. K. Parker. 
If we take the terrestrial, amphibious, and aquatic birds as a prac- 
tical half of the whole class, we shall find that the minor groups into 
which they break up all fuse into each other at their margins. 
If it were not for the fact that the Pigeons, Ardeine birds (e. g. 
Ibises, Storks, and Herons), and the “ Pelecanine ”’ have tender 
young, then a straight line might be drawn through the class, 
leaving on one side the plunderers, songsters, and other families of 
the ‘ Aves altrices,”’ and on the other the walking, running, wading, 
swimming, and diving birds. As it is, however, this interdigitation 
of the two main halves does not take away the great naturalness of 
such a subdivision ; and the land- and water-birds may be considered 
as together forming a very natural group. 
Certainly these birds have very much in common; and inosculant 
forms so completely connect together the minor subdivisions as to 
make one seamless web of these apparently incongruous materials. 
This slow but sure melting of family into family, and genus into 
genus, this mixing of single types so as to form double, triple, and 
multiple types, makes the ancestral hypothesis very hard to digest, 
whilst yet it seems to be the only one at hand having any scientific 
value. It may be an ignis fatuus, but, to one perplexed with tracing 
the mazy labyrinth of types, it looks like a light shining in a dark 
place. ; 
The Palamedea and the Kagu have turned up to me very oppor- 
tunely just now; they have made me rethink my thoughts, and re- 
peat and vary my observations, on the relationships of the land- and 
water-groups of birds. The former of these birds—the Palamedea— 
by bringing an essentially Anserine bird so near those outlying ‘“ Gal- 
line’ the Curassow and the Brush-Turkey, shows how it is that 
there exists so much in common in the skull and face of the Fowl 
and the Goose; whilst the Kagu, by tying closely together the 
Trumpeter and the Lurypyga, in some degree opens the eyes to 
understand why the relationship of the Cranes to the Herons, and 
of both to the Rails, should be so close and intimate. 
I have also been brought to re-analyze the families so as to elimi- 
nate, if possible, the single or pure from the mixed types, whether 
merely double or multiple. 
Tentatively and cautiously let us separate the true Ralline birds, 
from the Noftornis to the Coot ; this group may stand as one of the 
sinple-type families. 
Parallel with these birds—in some respects more intelligent, in 
others coming nearer to the reptile—we place the Plovers, not 
Ann. & Mag. N. Hist. Ser.3. Vol, xiv. 25 
