8 KANSAS UNIVERSITY QUARTERLY. 



The skull has been, unfortunately, almost wholly washed away, a 

 fragment of the cranial wall and the posterior part of the lower jaws 

 alone remaining. It is impossible, hence, to say much concerning this 

 part of the anatomy. The lower jaws show a different structure from 

 that in Pteranodon. As they lie in their natural position, the width at 

 the condyles is about twenty-four millimeters. The angular is less 

 produced posterior to the articulation than in Pteranodon., indicating 

 a less elongated and less powerful mandibular portion, an indication 

 further borne out by the slenderness of the rami. The impression in 

 the chalk shows the symphysis to begin ninety millimeters from the 

 articulation. The width at this place could not have exceeded sixteen 

 millimeters; and the entire length of the lower jaws could hardly have 

 been more than one hundred and twenty-five millimeters. In the 

 parts preserved, measuring seventy-five millimeters, there are no indi- 

 cations of teeth ; yet it is not impossible that there may have been 

 teeth in the anterior portion of the dentary, as in some species of 

 Ptcrodactyliis,. I hardly think it probable, however. 



There are seven cervical vertebrae preserved, apparently the full 

 complement, as in Pteranodon and other members of the order. They 

 differ in no especial respect from the corresponding vertebrae of Pter- 

 anodon, and, apparently, of Pterodactylits. The imperfectly anchylosed, 

 possibly free, atlas shows three pieces, the odontoid process and the 

 two slender lateral pieces. The lateral pieces are entirely free, with a 

 thickened base and a slender, curved upper portion. The odontoid is 

 gently concave in front, and seems to be imperfectly ossified with the 

 axis; it occupies, the lower part of the articulation, corresponding to 

 the hypapophysis of the Pythonomorpha. The axis is the shortest of 

 the remaining vertebrae, and has a well developed spine. The centrum 

 is strongly convex behind, as are the remaining centra of the 

 series. The following five vertebrae decrease gradually in length. 

 The anterior ones have only a thin ridge or plate for the neural spine ; 

 the seventh, however, has a neurapophysis of some length. They are 

 all, as is usually the case, somewhat distorted from pressure. The 

 under side is flattened, apparently gently concave longitudinally, and 

 with a lateral ridge terminating in an obtuse hypapophysis at each 

 inferior hind angle. 



In his discussion of the Pterosauria, Zittel says concerning the 

 vertebrae: "zwischen oberen P)0gen 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 verte- 

 brae is wholly or in part detached from the centrum, showing a sutural, 



