12 KANSAS UNIVERSITY QUARTERLY. 



the jaws; it agrees in every other respect with the genus Pterodactylus, 

 so far as known. If the genus has teeth it must be united with 

 Pterodactylus. Now, in not a few species of this genus, the teeth 

 are confined to the anterior end of the jaws, and their entire 

 absence, unaccompanied by other structural differences, will hardly 

 constitute an order, or even family. 



But, leaving aside Nyctodactylus, it is very much of a question 

 whether the differences between Pterodactylus and Pteranodon are 

 sufficient to locate them in different families, let alone different 

 suborders. 



The two genera have the following in common : Tail short. Skull 

 with more or less elongated, pointed jaws, and very small upper and 

 lower temporal fossae. Narial opening large, confluent with the pre- 

 orbital foramen. Cervical vertebrae elongated, with rudimentary 

 spinous processes. Fore and hind extremities, quite alike. 



Pteranodon differs from Pterodactylus, so far as that genus is known, 

 in the united coracoscapulae and pubes, both of vv^hich characters are 

 found in Rhaniphorhynchus. 



The sole family characters remaining then, for Pteranodon, are, 

 absence of teeth, a supra-occipital crest, and the articulation of the 

 upper end of the scapula. Now it seems evident that to place the 

 pteranodonts in a group equivalent to all the other pterosaurs is 

 unwarranted, and any classification that will not show the more pro- 

 nounced relationships with Pterodactylus is faulty. I would, therefore, 

 propose the following: 



Order Pterosauria. 



Family Pterodactylidae, subfamilies Pteranodontinae, Pterodac- 



tylinae. 

 Family Rhamphorhynchidae. 

 Family Ornithocheiridae. 



As regards the geographical distribution of the Pteranodonts, they 

 have hitherto been recognized only from Kansas, but I am firmly of 

 the opinion that they occur in Europe, and, if so, it is very probable 

 that the name Pteranodon must be eventually given up. In fact, a 

 toothless form of Pterodactyl was described by Seeley as long ago as 

 187 1, under the name of Ornithostonta. I cannot refer to his descrip- 

 tion at present, and can, therefore, give no opinion as to their identity. 

 It seems certain that the peculiar form of the scapulae and their 

 vertebral articulation * occur among some of the European forms, 



* The specimens in wliich I ha\'e seen tlie vertebral articulation show no 

 co-ossification of the vertebrae: the facet for articulation being placed above the 

 spines, and apparently formed by ossified ligaments. 



