283 



well developed proportionately as in Clidastes propython. Measurements of 

 the better preserved of the specimens are as follows : 



Lines. 



Length of the body interiorly - '.. 18 



Width of the ball and socket ..'. 12 



Height of the ball and .socket 10 



Clidastes affinis. 



Some remains submitted to my examination by the Smithsonian Institution 

 may perhaps indicate a species of Clidastes distinct from the former. The 

 specimens were discovered by Dr. George M. Sternberg, United States Army, 

 in the Cretaceous formation on the Smoky-Hill River, Kansas. • 



Fig. 6, Plate XXXIV, represents a nearly complete dentary bone, which 

 is accompanied by that of the opposite side. It contains the remains of a 

 series of twelve teeth, while there is one less in the other bone. 



The anterior extremity of the jaw is of rather less depth and slightly 

 greater thickness than in the corresponding part of Clidastes intermedins. 

 The splenial bone appears to have reached as far forward as the position of 

 the fourth tooth. 



The anterior teeth appear to have been larger, and the intermediate ones 

 smaller, than in C. intermedins, though this may have been a variable char- 

 acter in the same species. Portions of the bases of the crowns of several of 

 the back teeth exhibit the enamel strongly striated, and the surfaces of the 

 teeth also present evidences of subdivision into narrow planes. 



A fragment from the back part of a maxillary from the same individual 

 contains the bases of four teeth. The last of the series retains part of the 

 crown, which is strongly striated internally, and distinctly subdivided into 

 narrow planes externally. In the remains of the teeth of the specimens 

 referred to C. intermedins there is no trace of subdivisional planes to the 

 crowns, but this may have been a variable character in the species. 



Fig. 7 represents the back part of the right ramus of the mandible of the 

 same individual, seen on its inner side. It exhibits the same construction as 

 the corresponding part in C. propython. The articulation is nearly equally 

 divided between the angular and articular bones. 



Measurements of the jaw-specimens are as follows : 



Lines. 



Length of dentary bone 120 



Length of series of twelve teeth -. Ill 



Depth of jaw below first tooth 10 



