Ostcological Studies of the Subfamily Ardeince. 
5 
Passerine birds, and may be compared with the pro-coracoid of 
reptiles. Not having a young, or rather a sufficiently young 
enough heron, at hand, I am unable to investigate the pectoral 
arch with the view of ascertaining how the development pro¬ 
ceeds in the case of the forms under consideration. 
Professor Owen in calling attention to the relation between 
the hypocleidium of the clavicles and the carinal angle of the 
sternum in other birds, says : “ The process itself reaches the 
sternum, and is anchylosed therewith in the Pelicans, Cormorants, 
Grebes, Petrels, Frigate-bird, and Tropic-bird, also in the Gigantic 
Crane, and Storks in general.” 
I am compelled to take this 
statement with a little caution 
—as it does not always anchy- 
lose in the Cormorants, fails to 
do so in a number of the Podi- 
cipedidce , as in Clark’s Grebe ; 
and, so far as I am aware, rarely 
in the Procellar uda ; I have 
one or two exceptions before 
me ; the least tendency to form 
such a union being seen in the 
Grey Fork-Tailed Petrel, (Oce- 
anod ro m a fu rca ta ). 
In all of these forms, how¬ 
ever, the hypocleidium is in 
more or less intimate relation 
with the anterior border of the 
keel of the sternum. I have 
examples where the closeness 
of the contact is very intimate 
and requires special investiga¬ 
tion to determine whether true 
anchylosis really exists or not. 
This is so, even in Oceanodroma and Colymbus sometimes. I have 
several skeletons of the former before me, but have figured one 
where it was the least so. No doubt these facts accompanied by 
a lack of good material led Professor Owen to make the above 
statement. Unfortunately at the present writing, no skeletons of 
the Ciconiida are available to me ; although even in these birds, 
Fig, ii — Lefv i..».eral view of furcula cf 
A idea herodias. 
Fig. 12.—The same bone from in front. 
Roth life size from nature, and the same 
specinu n. 
