THE BIRDS OF AUSTRALIA. 
especially the Nyctibiince, in their general appearance, but they differ entirely in 
the structure of the palate, which is desmognathous, in the absence of the oil- 
gland, and of the basipterygoid processes, and also in the manner of their 
nidification. The t3rpical forms have a very broad and flat bill. The number 
of rectrices is always ten. The middle toe is not pectinated, the number of 
phalanges in the outer toe is not reduced. The sternum has two pairs of 
posterior notches . . . The young, when hatched, are helpless, but thickly 
covered with down ...” 
Hartert separated the family into two subfamilies, Podarginae and ^Ego- 
thehnse. I am regarding these divisions as of family rank. In the former only 
two genera were admitted, P odargus and Batrachostomus, the latter genus ranging 
from the Himalayas to Borneo and the southern Philippine Islands, the former 
being restricted to Papuasia, Australia and Tasmania. Hartert records as the 
chief difference between the two genera the difference in tail structure and the 
nesting habits. 
Mgotheles, as will be noted later, is a very different form. Though Hartert 
regarded the three species “ Podargus ” papuemis, strigoides and ocellatus as 
congeneric, I have separated them as distinct genera, the variation in size and 
wing formula being noticeable. It is now twenty-five years since the sixteenth 
volume of the Catalogue of Birds was written, and the advancement in our 
science in that time has been very rapid, from whatever viewpoint we regard it. 
Nomenclature, most unsatisfying and yet most important, has now reached 
a stage where it concerns us very little. Subspecific differentiation has also 
passed its climax, and the nomination of different generic and subgeneric forms 
has been mostly accomplished. It is now possible to go ahead as regards the 
osteology and anatomy of the forms and thus fairly fix the relationships. When 
this has been accomplished we will be able to theorise as to the origin and move- 
ment of the forms and begin to grasp the forces which control evolution. We 
may find the factors which in some cases retard, in others advance evolutionary 
changes. 
Thus, in the present case we have three forms of a group admittedly ancient, 
which so closely resemble each other as to be considered congeneric by the 
lumper. One of these ranges over the whole of Australia and Tasmania, show- 
ing well-marked subspecies, though of very variable coloration as a species, 
while the other two simply range into the north-east corner. One of these has 
an outlier weU down the east coast, which, isolated, seems to have arrived at 
an earlier period than its more northern congener. The other has no outlier 
but is confined to the northern limit of the continent, yet is a very marked sub- 
species. It seems that when the osteology and anatomy of these forms are made 
known that we shall find that our values of species and subspecies in this Order 
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