AXIAL SKELETON OF THE PELECANID^E. 337 



Besides the cervical and cervico-dorsal vertebrae, the first two or three dorsal vertebrae 

 are more or less movable ; but the last dorsal ankyloses with all the more postaxial 

 vertebrae to the end of the sacro-caudals ; and the lumbar and last dorsal vertebrae 

 have their centra more compressed laterally. 



The cervical vertebrae unite, as in Pelecanus, so as to form angles with one another, 

 open ventrad till the seventh's junction with the eighth, which forms an angle open 

 dorsad, as does that of the eighth with the ninth, and so on postaxiad till they unite 

 without forming an angle at all. 



THE CERVICAL VERTEBRAE. 



These vertebrae, when compared with those of Pelecanus, present differences more or 

 less analogous to the differences presented by those of Casuarius compared with those of 

 Struthio and Ehea ; for the vertebrae have become individually shorter antero-poste- 

 riorly, and at the same time more rugged and ridged, with relatively more prominent 

 processes. 



The ATLAS presents a small odontoid-foramen (of) instead of a notch. The neural arch 

 is larger antero-posteriorly, with long postzygapophyses, generally making the post- 

 axial margin of the neural arch more concave. The hypapophysis is decidedly more 

 developed (Plate LVI. figs. 1 & 2). 



The AXIS has its neural arch cut off still more obliquely preaxially ; the hyperapo- 

 physes are very much more developed, and the hypapophysis enormously so : it 

 projects ventrad and slightly, or much, postaxiad ; and its summit has two small vertical 

 grooves, bordered by one median and preaxial and two lateral ridges. Two minute 

 processes project from near the preaxial end of the ventral surface, near its middle ; and 

 another projects above each on each side, being placed a little more dorsad as well as 

 postaxiad (Plate LVI. fig. 3, ps). 



The postaxial articular surface of the centrum has its dorsal margin even slightly 

 longer than its ventral one. 



There is no pleurapophysial lamella ; but there is a conspicuous foramen on each side, 

 leading into the substance of the bone, and situated at the ventral part of the strongly 

 marked lateral fossa produced by the much stronger projection here than in Pelecanus 

 of the interzygapophysial ridge (?'z). The margin of the neural spine, viewed laterally, 

 is less convex. 



The whole neural arch hardly projects so much postaxiad of the centrum as in the 

 genus first described. 



The THIRD VERTEBRA is shorter than in Pelecanus, relatively as well as absolutely, 

 being no longer than the axis ; it is more concave laterally ; the neural arch is more cut 

 away preaxially. The hyperapophyses and hypapophysis very much longer, the latter 

 having preaxially still three ridges and two vertical grooves towards its extremity. The 

 lateral vertebral canal is much shorter, and very much more capacious, even absolutely. 



