In his discussion of the Pterosauria, Zittel says concerning the vertebrae: “zwischen oberen Bogen und Centrum ist keine Sutur zu bemerken.” Handbuch, iii, p. 776. In this he is in error, so far as the American forms are concerned. It is usually the case in the Kansas specimens of both genera that the neural arch of the post-cervical vertebrae is wholly or in part detached from the centrum, showing a sutural, and not anchylosed 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, horizontal 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 (_b_), found close by the one just described, and possibly one or the other contiguous with it, differ remarkably in having no, or a rudimentary, parapophysial process, and in having the diapophyses much shorter. It is not impossible that a slight expansion at the lateral margins of the ball may represent small parapophyses. In _Pteranodon_ there are at least four vertebrae with dia- and parapophyses. In the other vertebrae from this region the diapophyses 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.