MR. W. K. PARKER ON THE OSTEOLOGY OF BALANICEPS REX. 323 
This table of the numerical relations of the vertebral columns of certain birds, several 
of which birds are related to Baleniceps, will be referred to more than once in the descrip- 
tion of this part of the skeleton. The great difficulty has been in enumerating the sacral 
vertebre ; but much care has been taken to examine sections and immature specimens ; 
and where these have not been obtainable, the twin nerve-outlets on each side have 
been carefully counted. In some cases a doubt has been expressed; and in others, 
rather than err, we have left out the number in that column. The most important 
birds for comparison with the Baleniceps are those Grallz which have short but 
compressed bodies, or short, stout, robust bodies, with only five pairs of thoracic hema- 
pophyses, the last pair of which may reach the sternum, as in the Ciconie, the Bale- 
niceps having the same structure, or may be floating and imperfect, as in Ardea and 
Cancroma. The latter birds, as well as those of the genera Aramus, Scopus, Botaurus, 
Nycterodius, Erodius, and Baleniceps, have the chest flat, or compressed, whilst the 
Ciconie and Mycterie have a round full-shaped body. In the more distantly-related 
Cranes, and in the still more unrelated Gallinules, Rails, and Coots, the thorax is long 
as well as compressed, the compression being greatest in the latter group. 
Flat compressed bodies are the rule amongst the Gralle, the Rallide carrying that 
character to its extreme condition, whilst most of the Palmipeds have broad depressed 
bodies. The extreme of this opposite character occurs in the genera Podiceps and 
Colymbus. 
We see by the above table that the Baleniceps has the same number of vertebrz in 
the entire spine as the Heron, three more than the Boat-bill, one more than the 
Adjutant, and two more than the White Stork. The diminution of the number of 
vertebrz in the Boat-bill is explained by its being a small and comparatively feeble 
form of the same type; for, other things being equal, a large bird has a greater number 
of vertebrze than its smaller congeners; and small birds, generally, have relatively 
shorter spines than large ones—-the neck and sacrum being the parts in which this 
diminution most takes place. A glance at the table makes this clear, although the 
instances are but few; yet they could have been multiplied indefinitely. However, it is 
worth while to remember that the little Humming-bird has only thirty-four vertebre in 
all; the Swift (best of fliers) only thirty-six ; whilst the Emeu has fifty-seven. It is not 
intended to say here that the three last-mentioned birds are in the least congeneric ; 
yet the rule will be found to hold good, as a general principle, in families as well as in 
the broad class. 
Looking at the skeleton of this great Wader, we see one of the most striking instances 
of an aberrant form, conformable in all essentials to its type, and yet having structural 
affinities with all the families that lie in the region round about that central type. 
When the skeleton has been described, and the curious affinities of the bird, whether 
patent, or more secret, have been shown, then perhaps some attempt will be made to 
prove that the Balzniceps is only one amongst many wanderers from typical restraint, 
and that all these aberrants are still ‘ under law.’ 
