150 Zoological Society. 
This table is large enough for all reasonable purposes ; and its re- 
sults are very striking, and cannot have had their extreme uniformity 
caused by chance. If we leave out all those birds which, for swim- 
ming and especially diving purposes, have the sacrum extremely long 
and much anchylosed, such as the Sifters, Grebes, Loons, Cor- 
morants, and also the Ostriches (excluding the Apteryx), we shall 
have four post-acetabular joints as the medium number. A large 
proportion of all birds have exactly four vertebree in rear of the 
thigh-bones; many have only three, and about as many more have 
five. Asarule, the small birds of a group have the tendency to drop 
a joint occasionally ; thus the little Hstre/da has one less than the 
other Finches, the Dotterel one Jess than the other Plovers, and the 
Crake one less than the other Rails. The medium-sized rapacious 
birds, both nocturnal and diurnal, have only three. Now, if we con- 
sider that all the vertebree above four in the posterior part of the 
Duck’s pelvis really belong to the tail, then, as I long ago found, the 
ploughshare-bone is composed of ten segments, as four of the ap- 
parently sacral bones are really caudal ; and as there are eight inter- 
mediate vertebrze, the large number of twenty-two is obtained—one 
more than the Archeopteryx possesses according to Professor Owen’s 
method of enumeration. 
Also in the Palamedea two of the anchylosed bones belong to the 
tail; there are six free bones, the last having had a rather late ad- 
dition in the penultimate joint, so that it may be considered as 
eleven : this gives us nineteen caudal vertebree for the subject of this 
paper—only two less than in the Archeopteryx. The same method 
gives us twenty-four for the Swan, sixteen for the Emeu, and twenty- 
two for the Cormorant. 
That five of the so-called sacral vertebree of the Palamedea belong 
to the dorso-lumbar region is evident, because the first three have 
heemapophyses reaching the sternum, and on the right side there 
are two more sternal ribs in a rudimentary condition. There are 
seventeen vertebree fused together, five of which must be supposed 
removed from the front part and two from behind, thus leaving ten 
proper sacral vertebree. 
In small birds and in birds of the higher types with short pelves, 
the number of true sacral vertebrae will be only about seven on an 
average—a common number among the large herbivorous Mammalia. 
As I have only touched upon the points of interest in this skeleton, 
when I have acquired a fuller knowledge of it and of its congeners, 
and of the bearings and relations of the feathered tribes generally, 
I hope to take it up again. Certainly amongst living birds there 
is not one possessing characters of higher interest; none that I am 
acquainted with come nearer, in certain important points, to the 
Lizard ; and there are parts of its organization which make it very 
probable that it is one of the nearest living relatives of the marvel- 
lous Archeopteryx*. 
* The cup-and-ball joints in the dorsal region of many water-birds and of the 
Parrots must be looked upon as a general reptilian character; so also the single 
head of the “ os quadratum’”’ in the Ostriches. The very simple palatines of the 
latter birds and of the Palamedea, the very long free toes and the simple ribs of 
the Screamer, all these are more properly Jacertian. 
