C. W. Andreivs — JEpyornis from Madagascar. 



243 



bears on its inner face the nearly circular posterior zygapopbysis, 

 which looks inward and backward ; above this there is a strongly 

 developed hyperapophysis. The lower lobe consists of a downwardly 

 and backwardly directed process, the base of which is perforated by 

 a large foramen ; it seems to be homologous with the process in the 

 atlas of Bhea, which is regarded by Mivart as the diapophysis. At 

 the same time the perforation of the base gives it much the 

 appearance of a fused cervical rib, of which the capitulum has 

 shifted up into the arch. The posterior border of the middle of the 

 neural arch is deeply concave : the anterior has been broken away. 



Fig. 1. — A. Atlas of ^pijornis from front and side. 

 B. Axis ,, ,, ,, 



All the figures natural size. The axis helonged to a rather larger individual than 

 the atlas. 



The atlas thus differs widely from that of Strutliio in the 

 completeness of the cup for the occipital condyle, the absence of the 

 costal element enclosing a vertebrarterial canal, the presence of 

 a large diapophysis, and the absence of a median hypapophysis. In 

 the first three of these characters it differs also from Dinornis. Of 

 the other Eatitee, Bhea most resembles this specimen, in the 

 structure of the atlas, the form of the arch, and in the anterior 

 articulation being closely similar ; in Dromceiis also there is no 



