3 
groove with evenly raised margins on either side and a large, deep exca- 
vation immediately under the head marking a pneumatic foramen. This 
foramen is undercut beneath the head above and on the outer side, and 
has an abrupt but sloping wall on its inner face and below. At its bottom 
there is a trace of a median septum dividing it longitudinally in two sec- 
tions. The tubercle for attachment of the tibialis anticus lies at the centre 
of the anterior groove at the lower margin of this foramen. There is a 
second tubercle for tendinal attachment on the outer wall separated by 
a narrow but distinct sulcus from the tubercle just described. External 
to the pneumatic foramen is a relatively broad, shallow" groove with 
sharply crested margins. The external face of the head is broad and 
smooth, slightly convexly rounded for its anterior half and then changing 
to a faintly concave line toward the base of the talon. The inner face 
also is broad with a somewhat more angular surface that in general has a 
slight convex outline. The hypotarsal crests are missing, so that their 
former position is indicated merely by broken surfaces of bone. The outer 
crest of the talon had a long and very narrow base, extending proximally 
to the transverse groove on the articular surface, and distally to a level 
equal to that of the lower margin of the tibialis anticus tendon. It is 
separated from the line of the inner crest by a shallow groove, at the 
anterior end of which is a large pit that apparently led into the pneumatic 
centre of the shaft. The base for the inner crest was much broader, and 
was approximately as long as the outer crest. It was broader in front 
and narrowed behind and had a foramen entering the centre of the base on 
the outer side. The outer face of the base is marked by a broad, shallow, 
longitudinal groove. It would appear that the outer crest was high and 
blade-like and the inner broad, probably low and flattened, and perhaps 
divided by a groove into two portions. The shaft below the talon on the 
posterior surface in outline is irregularly rounded. The shaft was thin 
walled and highly pneumatic. 
The specimen has the following dimensions: transverse breadth of head 
at level of upper margin of pneumatic foramen, 36 >7 mm.; transverse 
breadth of shaft at lower end of fragment, 24-8 mm.; breadth of anterior 
pneumatic foramen, 10-8 mm. 
On careful comparison with pertinent modern birds it is easily apparent 
that Cyphornis is most closely allied to the Pelecanidae. The anterior 
aspect of the bone in particular closely resembles that of Pelecanus onocrotalus 
and jP. erythrorhynchos . There is the same general form, the deeply 
excavated pneumatic foramen, and also the highly pneumatic character 
of the bone. In the anterior face, Cyphornis differs mainly in the higher, 
longer ridge on its internal border and the broader space separating the 
intercondylar tubercle from the pit below. 
In size Cyphornis was more than twice as large as the largest of 
pelicans, so that it was a giant in its order, standing perhaps 6 feet in height. 
Cope has remarked that if it had the ability to fly it represents the largest 
known flying bird in the New World. Its dimensions may be appreciated 
when it is known that in the largest specimen of Pelecanus onocrotalus 
at hand the transverse breadth of the metatarsus taken at the same level 
as in Cyphornis is only 25*6 mm. 
