PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 73 



Measurements of humerus Miilimetera 



Greatest length 183. 



Greatest width of proximal end 42.0 



Greatest vridth of distal end 57.5 



Least diameter of shaft 17.5 



Anteroposterior diameter of head 20.5 



Anteroposterior diameter of distal end 28.0 



Vertebrae. — The vertebral column is represented by two vertebrae 

 that are fully coossified. These are uncrushed, and except for the 

 loss of the tops of the neural spines and ends of the transverse 



Fig 1 — Left humerus of Pteeanodov ( ') oeegonensis. Type. 

 a. Posterior a iew , h, anterior view , c, externaij view ; d, proxi- 

 mal VIEW. All figures one-half natural size 



processes are in an excellent state of preservation. Comparisons 

 made with the vertebral column of Pteranodon seems to indicate 

 their position to be in the posterior dorsal region. The position of 

 the transverse processes, which have their origin above the level of the 

 neural canal, centra constricted at the middle with expanded ends, 

 and steep inclination of the zygapophysial facets are all features 

 indicative of their posterior thoracic position as shown in Figure 2. 

 In Pteranodon the dorsal series consists of eight anterior coossified 

 vertebrae, which is designated the notarium, and they are followed 

 by either three or four free vertebrae which fill the interval between 

 the notarium and the coossified series forming the sacrum. 



