9o6 



S TEREORNITHES 



quadrate articulates with the squamosal by two distinct heads, a 



Phoroehacos iKFLATUS. Head from the sicle. (After F. Ameghino.) 



condition of which remnants may be traced in Rhea and Drommis, 

 though not in other Ratitm, and the mandible has its hinder end 



truncated as in Rhea. Unfortunately the 

 sternum is still unknown, but the coracoid 

 is narrow and elongated, the furcula very 

 slender and almost rudimentar\", yet the 

 Avings, 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 

 vertebrae. 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- 



-s: N ized by the length and narrowness of the 



o,„ ^-^ trough -like symphysis, and the moderate 



Phororhacos inflatus. o ^ r j _' 



Head from above. divergence of the rami. In the typical P. 



(After F. Ameghino.) longissimus the wholc length of the mandible 



is about 21 in., and the medium breadth of the symphysis 2-5 in. 



