Osteological Studies of the Subfamily Ardeince. 
the subject, I believe the formula for the manus of the Herodiones 
will be found to be—pollex metacarpel, with a digit composed of 
two phalanges ; index metacarpus, with a digit of three phalanges ; 
and middle metacarpus with a single phalanx to its digit. 
So far as the material goes that I have 
been able to examine, the pectoral ex¬ 
tremity among the Ardeince offers no 
very striking differences. As a good illus¬ 
tration of the slight departure that is 
made from a common plan among these 
Herons, no better example could be offer¬ 
ed than the series of bones shown in fig¬ 
ures 35, .36 and 37, being the right hu¬ 
merus from Ardea herodias , Nycticorax 
and A. candidissima. 
\ 
Of the Pelvic Extremity. —After the 
most careful examination of the material 
at hand, I find it is only in the femur of 
Nycticorax that pneumatic foramina ex¬ 
ist. These are exceedingly minute, 
though they may be detected without the 
aid of a lens just over the border of the 
anti-trochanterian facet on the posterior 
aspect of the bone. In A. herodias and 
A. candidissima the femur, as well as all 
the other bones, composing the skeleton of 
this limb, are absolutely non-pneumatic. 
Our Great Blue Heron has a femur 
fully as long as its pelvis omitting the 
free, posterior end of the pubis. Its head 
and neck make nearly a right angle with 
the shaft, the former being hemi-globular 
and much excavated for the ligamentum teres, while the latter is 
short and thick. At the summit of the bone the anti-trochanterian 
facet is broad and extensive. From before, backwards, its surface 
is convex ; in the other direction, that is from the head to the 
trochanter, it is concave, becoming gradually wider as it ap¬ 
proaches the latter. 
The trochanterian ridge does not rise above this articular sur¬ 
face to any perceptible degree, but becomes rather prominent as it 
Fig. 30 .—Nyctiaorax violaceus. 
juv. Its mandible from 
above: life size ; same speci¬ 
men as figures 2S and 29. 
