746 GEOLOGICAL SURVEY OF THE TERRITORIES. 
anterior base of the bone. This is a constant character and is only to be 
observed in Cathartes aura. The palatines are broad plates of bone, with 
a wide fissure separating them; anteriorly their extremities are wedged 
into the anchylosed articulation in common with the lateral processes 
of the premaxillary and themaxillaries. The posterior and upper thirds 
of their inner margins are fashioned to glide over the interior and 
rounded surface of the sphenoidal rostrum, the articulation being a re- 
markably free one. Their posterior ends turn outwards and accommo- 
date themselves to the entire crown of the heads of the pterygoids 
(Plate XXII, fig. 120), constituting the usual pterygo-palatine articula- 
tion. Descending lamina are developed from the inner margins of 
these bones, along the posterior half of the palatine clefts in all of 
the species. There is a disposition on the part of these plates to curve 
downwards, so that their outer margins are in a lower plane than their 
inner ones, their surfaces being smooth, and as a general thing their 
salient angles rounded. G. papa, in comparison With its size, seems to 
possess the largest and widest palatine bones of any of the Cathartida, 
while C. atrata has the narrowest. 
The sutural traces of the three primary segments of the infraorbital 
bar have all disappeared, and we have remaining only the strong style 
that bounds on either side the orbital cavity below. On the inner side 
of its posterior end we observe a conical tooth-like apophysis placed at 
right angles with the continuity of the bone that fits deeply into a 
socket intended for it on the lateral aspect of the quadrate. The distal 
extremity of this malo-zygomatic link is tirmly wedged into the articu- 
lation described above, being superior to the palatine, and slightly 
dilated in the horizontal plane, as the maxillary usually is. This bar 
has a gentle fall from before backwards until it arrives at the os quad- 
ratum. In Pseudogryphus it is much compressed from side to side, and 
presents a decided vertical swell in its anterior third. (Plate XVI, fig. 
106.) 
So large are the quadrate bones in the skull of any of these Vultures 
that they form one of the most prominent features on the lateral view 
of the cranium. The ‘‘mastoidal process” looks very much as if it 
might originally have been a broad lamina of bone, facing directly 
forwards, but subsequently had been seized by the condyle, twisted 
one-third upon itself, and its articular facet placed in the concave 
depression in the squamosal; the long diameter of this latter lies in an 
oblique direction, and if its imaginary line were produced it would pass 
from the upper and outer margin of the auricular process towards the 
occipital condyle. This articular facet on the mastoid process is long 
and narrow, being convex from side to side, as well as from above down- 
wards. The orbital process of either quadrate, though it looks very 
formidable from a lateral view, consists merely of a very thin, though 
broad, oblong lamina of bone, projecting ata right angle from the stouter 
mastoid process into the orbital space. Its inner extremity is finished 
off by a little raised rim. At its base, above the inner condyle of the 
mandibular end, we have presented to us for examination the sub-ellip- 
tical convex facette for the pterygoid, a special elevated crest being 
thrown out to support it. In all, with the exception of aura, a marked 
depression occurs just anterior to the articulation and immediately 
above the inner mandibular condyle. The Californian Condor seems 
to have this characteristic best shown. The condylar surface on the 
under side of the quadrate intended for the lower jaw is, aS usual in so 
many birds, divided into two irregular, undulating facets, separated by 
a mid-depression; the long diameter of the whole being situated trans- 
