Hutton. — The Axial Skeleton in the Dinornithidce. 167 



Thoracic Vertebra. 



The post-axial surfaces of the centra are narrow. The 

 anterior pneumatic foramen does not descend below the rib- 

 facet. The posterior pneumatic foramen is well developed. 

 The post-zygapophyses form an acute angle with each other, 

 and the pre-zygapophyses are short. 



Pelvis. 



Narrow. Centre of ilium half-way between centre and 

 anterior margin of acetabulum. Pre-axial portion of ilia 

 rather low, and sharply ridged ; dorsal margin nearly straight 

 axially. The ilia begin to diverge behind the anterior margin 

 of the acetabula, and extend backwards to vertebra No. 46. 

 Ischia generally extending slightly beyond the ilia. Lateral 

 surfaces of post-acetabular portion of ilia the same as in 

 Meionornis. Ventral surfaces of sacral vertebrae long, not 

 ridged. Transverse processes of posterior vertebrae more 

 oblique and stronger than in Meionornis. 



Sternum. 



Body quadrate ; the anterior margin strongly curved 

 dorsad, the costal processes long and directed dorsad also. 

 Coracoid depressions deep and oval. Shallow pneumatic 

 depressions on the inside at the antero-lateral corners. 

 Lateral processes stronger than in Meionornis. Scapulo- 

 coracoid about 3^in. in length, of which the coracoid occu- 

 pies one-third ; not much expanded at the anchylosis. 



Genus PACHYOENIS, Lydekker. 

 Euryapteryx, in part, Hutton. 



Section A. Type — P. immanis, Lydekker. 



The following description is taken from a nearly-complete 

 vertebral column found with the skull, sternum, pelvis 

 (fragmentary), and most of the leg-bones, the latter being 

 typically immanis. 



Cervical Vertebra. 



Anterior cervicals — 3 to 6 — have the post-axial surfaces of 

 the centra more quadrate than in any other genus, the height 

 being equal to the breadth in No. 4, slightly greater than the 

 breadth in No. 3, and less than the breadth in No. 5. 

 Greatest breadth of No. 3 is 38mm. (l*5in.). The neural spine 

 is divided nearly to the base on Nos. 3, 4, and 5. The zygapo- 



