294 University Geological Survey of Kansas. 



two species mentioned above, I am inclined to think that these 

 will have but little specific value until the type specimens of 

 each are redescribed and figured in a way to render them recog- 

 nizable. 



The specimen, No. 155, consisting of the upper and lower 

 jaws almost complete, fragments of the skull, and numerous 

 vertebrae, was collected by Prof. B. F. Mudge from the Niobrara 

 Cretaceous, four miles north of Gorham, Kan. 



The premaxilla is somewhat oval in outline, and the anterior 

 portion is thickened instead of the central, as is usually the case 

 in X. audax. The posterior border is thin, and is peculiar in 

 having the internal side of the bone beveled off to meet it, some- 

 what similar to that found in Ichthyodectes and Saurodon. The 

 alveolar border is quite elongate, and supports three teeth on 

 one side and an empty alveolus for a fourth, all of which are 

 small, with the exception of one. 



The maxilla is especially characterized by the manner in 

 which it unites with the premaxilla, for instead of having the 

 abrupt change to the laminar portion in front of the posterior 

 condyle, the bone is gradually beveled off to a sharp anterior 

 edge, similar to the condition found in Ichthyodectes. Both of 

 the superior condyles seem to be small, and the anterior one is 

 directed inward to a considerable extent. The two are well 

 separated from each other. The bone is quite deep at the pos- 

 terior condyle, and the superior border, back of it, presents a 

 conspicuous groove for the attachment of the jugal. There are 

 nineteen or twenty teeth on one side, the most of which are 

 small or medium in size. 



Premaxilla : Length of alveolar border 62.0 Him. 



Greatest depth of bone 90.0 " 



Maxilla : Length of alveolar border 220.0 " 



Depth of condyle 83.5 " 



The dentary bones are short and deep, thus giving them a 

 very robust appearance. The bones are much thickened at the 

 symphysis, and slope backward nearly as much as in X. lowii. 

 The alveolar border is short and is remarkable for the small 

 number and large size of the teeth toward the anterior extremity. 



