185 
bridge. The margins of the groove whence the bridge springs in 
Dinornis are in Dromornis broadly convex and entire.” And 
again, in Mr. Etheridge’s paper so frequently referred to,* it is 
stated, in speaking of the Paroo River fossil, that ‘‘ the rounded 
edge of the precondylar groove at that point in the present bone, 
whence in Dinornis the piers of the bony bridge, or oblique bar 
would spring, are much worn away, and would at first convey the 
impression that a similiar structure had here existed. By follow- 
ing the general contour of the groove, however, and comparing 
with this the mechanism in a Dinornis tibia it is quite apparent 
that such a structure could not have existed in the present 
instance, and we are therefore dealing with a true Dromornis 
bone.” Now the preciseness of these statements and the sources 
from which they emanate are of such a character that it requires 
some assurance to suggest that they have been made in error. 
Further, we should have ourselves to admit that, had our own 
notice been based upon some of the Callabonna bones, we should 
have been compelled to make a similiar assertion as to the absence 
of a bony bar. We have specimens in which the margins of the 
groove at the site of the bridge are so worn as to leave no trace 
of the previous existence of such a structure. Fortunately, 
however, in one specimen the bridge is 17 situ and perfect in its 
form and attachments; in two others the osseous attachment 
to one pier is intact though, on the opposite side of the groove, a 
narrow gap, extending though the whole width of the bar, separ- 
ates the end from its corresponding pier; in others, though the 
bridge itself is absent, the condition of the margins clearly 
indicates its former existence. Mr. Pittman, Director of the 
Geological Survey of New South Wales, has very courteously 
forwarded the Paroo River fragment for our examination, and 
we find that the appearances presented by the piers in this bone 
are exactly paralleled by those of some of the Callabonna tibie. 
We have, therefore, no hesitation in asserting that the bar was 
once present in this bone also. 
As to the Mt. Gambier specimen described by Professor Owen, 
we are only able to refer to his plate. The margins of the groove 
where the bridge ought to be are there certainly shown as in a 
very worn condition, but not more so than in some of our own 
specimens, while there is so close a correspondence in other 
details of the bone that we have no doubt of its identity with 
the tibia of Genyornis. 
In the tibio-tarsus of Genyornis there is a much more abrupt 
inward deflection of the tendinal groove, which takes place just 
at the place where it is spanned by the bridge, than we find in 
* Op cit. 
