906 STEREORNITHES 
quadrate articulates with the squamosal by two distinct heads, a 
PHORORHACOS INFLATUS. Head from the side. (After F. Ameghino.) 
condition of which remnants may be traced in Lea and Dromexus, 
though not in other atitx, and the mandible has its hinder end 
truncated as in thea. Unfortunately the 
sternum is still unknown, but the coracoid 
is narrow and elongated, the furcula very 
slender and almost rudimentary, yet the 
wings, though relatively small, are com- 
pletely developed. The pelvis is very re- 
markable, being narrow and elongated, and 
has the ischia produced beyond the ilia, 
with which they are fused. Its preace- 
tabular portion is short and the postace- 
tabular very narrow. ‘The tail is long with 
a relatively considerable number of separate 
vertebre. There is no pneumatic foramen 
in the femur. The tibio-tarsus has a pro- 
minent cnemial crest, a distal extensor 
bridge and a deep intercondylar groove, the 
condyles themselves being very prominent. 
The tarso-metatarse is moderately or con- 
siderably elongated, with the proximal 
intercotylar tuberosity strongly developed, 
and the upper part of the anterior surface 
deeply grooved. In all cases a hallux is 
present. 
In Phororhacos the mandible is character- 
ized by the length and narrowness of the 
trough-like symphysis, and the moderate 
PHORORHACOS [NFLATUS. 3 : ¢ 
Head from above. divergence of the rami. In the typical P. 
After F. Ameghino. atts l 
(After epee) longissimus the whole length of the mandible 
is about 21 in., and the medium breadth of the symphysis 2°5 in. 
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