4 Osteological Studies of the Subfamily Ardeince. 
the lower process, in this bird, equals the upper in length, and as 
a whole is comparatively slenderer (Fig. 33). 
Figure 34 gives a three-quartering view of the fiircula of my 
specimen of A. candidissima. It will be observed that it differs 
in no important particular from Ardea , though the anterior sur¬ 
face of the lower process of the hypocleidium is longitudinally 
grooved, a feature which, by the way, I neglected to say, is 
faintly indicated in the latter heron. 
A glance at any of the figures representing this bone in the 
Ardeince , is sufficient to satisfy one that it is a very different affair 
Fig. 10.—Right lateral view of coraeo d and scapula. Ardea lierodias. Life size 
from nature. 
from the corresponding part of the pectoral arch in such forms as 
Sula, Phalacrocorax , or Pclccanus. In these latter types the united 
clavicles arch backwards to meet the carinal angle of the ster¬ 
num, here to articulate with it, or even as in Tachypetes and very 
old Cormorants to actually anchylose with it. The lower part of 
the furcula in Herons, is, on the other hand, turned forwards 
from the sternum, assuming a curve not often seen among birds. 
Anatomists have termed the clavicular head in birds, the 
epicleidium, and this end of the bone, according to Professor 
Parker, ossifies as a separate piece in some forms, notably the 
