9 
Osteological Studies oj the Subfamily Ardeince. 
the massiveness of the osseous column upon which the pelvis of 
this Heron is built. 
The acetabulum is large and circular, with its floor more 
than usually deficient, the inner ring nearly equalling in size the 
outer, while the antitrochanterian articular surface is carried by 
them both as it passes inwards. Externally this facet looks 
downwards and only slightly outwards. 
The ischiadic foramen is large and sub-elliptical ; its major 
axis being parallel to the line of the outer border of the post-ace- 
tabular surface, which here arches over it. Posterior to this fora¬ 
men, the broad part of the ischium is roughly quadrilateral in 
outline, and for the most part smooth and slightly concave. It is 
nearly at right angles with the iliac surface above it. In this 
—Right lateral view of the pelvis of A. heroclias, same bone shown in Fig. 13. 
heron the obturator foramen is far from complete or deserving the 
name of a foramen. Nearly its entire posterior arc is deficient, 
and the opening thus created, leads into the obturator space, 
which latter is found beneath the entire lower margin of the 
ischium, being broadest in front and gradually tapering off 
behind (Fig. 14). 
Ardea herodias has a blade-like pubis, of nearly an equal 
width throughout, though rather wider behind, after it parses the 
ischium and curves mesial towards its fellow. Just before it does 
this it is slightly over-lapped by the lower and posterior angle of 
that bone, or else meets it in a single point of tangency, or, as in 
the figure, does not quite come in contact with it. Quite a large 
pneumatic foramen is found beneath the projection of each ilium 
immediately behind the anti-trochanter. 
