williston: Kansas pterodactyls. 9 



and not anchy- losed union in life. The centra of twelve vertebrae are 

 preserved, in the present specimen, from the region back of the neck ; in 

 only five of them are the neural arches in any way attached. Three of 

 these are evidently anterior thoracic, judging from their structure and the 

 position in which they lie. The shortest of them, to which was 

 attached a very large rib, and which was lying in front of the scapulae, 

 may represent the first thoracic vertebra (a). Its centrum is fully as 

 wide as long, is flat on the under surface, and has a large, stout, hori- 

 zontal parapophysis near the anterior end. Just above this process 

 for the attachment of the head of the rib, and separated by a deep 

 notch, is a much more elongated, horizontal diapophysis for the 

 tuberculum. The cup of the centrum is shallowly concave ; the 

 transverse, shallowly U-shaped ball is only a little convex. 



Two other vertebrae (d), found close by the one just described, and 

 possibly one or the other contiguous with it, differ remarkably in hav- 

 ing no, or a rudimentary, parapophysial process, and in having the 

 diapophyses much shorter. It is not impossible that a slight expan- 

 sion at the lateral margins of the ball may represent small parapo- 

 physes. In Fteranodon there are at least four vertebrae with dia- and 

 parapophyses. In the other vertebrae from this region the diapo- 

 physes are yet shorter and the neural spine stouter and broader. 

 The other centra preserved are all shaped somewhat like the half 

 of a cylinder, and are a little longer than broad. They have no 

 distinct cup or ball. In two of them there is a very long, recurved 

 parapophysial process, as though formed by an anchylosed rib, on 

 each side ; they are probably lumbar vertebrae. 



Most of the ribs are very slender ; a few are moderately thickened ; 

 one only is very stout ; its measurements are given below. 



Length of lateral pieces of the atlas 7 millim. 



Diameter of lateral pieces at the base 3^2 



Width of odontoid 4}^ 



Height of odontoid 3 



Length of axis 8 



Height of axis 15 



Length of third cervical vertebra 21 



Length of fourth cervical vertebra 20 



Length of fifth cervical vertebra 19 



Length of sixth cervical vertebra 18 



Length of seventh cervical vertebra 17 



Height of seventh cervical (about) 15 



Length of centrum, anterior thoracic vertebra {a). ... 6 

 Width of ball {a) 8 



