Osteological Studies of the Sub-Family Ardeince. 5 
superior region of tire upper mandible, and were it not fc it, 
these two surfaces would be continuous, gradually mer ng 
into each other, which indeed they almost appear to do 1 w. 
The frontal region is broad between the superior margins of he 
orbits, faintly venated, and depressed longitudinally in the mi lie 
line. 
In the skulls of Sula bassana and Pelecanus fuscus , specii 11s 
of which I have before me, this region is likewise very broad nit 
the median depression does not exist, it being but faintly 111a ed 
in the parietal region in these birds. 
Upon this upper view of the skull of this Heron, we ay 
also see the superior aspects of the long and laige lacryi Is. 
They fit closely to the sides of the frontals, and anteriorly en¬ 
croach upon the external borders of each nasal. 
The posterior orbital margins are pierced by a few mi ite 
foramina on either side, into which the larger venations coi ng 
from the parietal eminences lead. These latter are quite stro ;ly 
marked here as they are in other Herons. Among the Pelc .ns 
and Gannets, however, this region is not thus distinguis ed. 
Still more posteriorly on this aspect we observe the very b ad 
fossa on either side, known as the “ crotaphyte fossa.” The in¬ 
terior margin of those fossae, passes directly across the si .11, 
being simply interrupted in the middle line by a small triang lar 
jog, with its apex directed backwards and continuous with lie 
median line dividing the fossae. Laterally, these fossae pass iu 
between the sphenotic and squamosal processes, occupying he 
entire space. Posteriorly, they are bounded by the supra-occi tal 
line, and a muscular line, on either side, leading to the squall sal 
process. Fig. 1. 
This description of the crotaphyte fossae of Ardea hero zs, 
answers with equal exactness, for the same depressions as f< nd 
in Ardea candidissima , a specimen of which I have before ie. 
I11 the Yellow-Crowned Night Heron, their form differs materi ly, 
(Fig. 29), as well as their position. We observe in this bird iat 
these depressions are separated from each other in the 111c an 
line, by quite a broad isthmus, which meets the apex oi he 
supra-occipital line. The region below this latter, presenti ■; a 
prominent, though rounded median crest. I11 the Night H( m, 
(W. violaceus ), too, it can be said, that they are more on a in¬ 
terior aspect of the skull, rather than on top. This fact is t ter 
