233 



continuous with that of the rising lamina. The tongue-shaped bone is flat. 



and expanded behind. The dentary is acuminate distally ; and the mental 



foramen issues in a groove, which passes round the distal end. The inferior 



external fossa commences some distance behind the foramen. External face 



of dentary striate. 



Measurements. 



M. 

 Lcugtli of the prennixillary and maxillary (reconstructed from fragments from opposito sides). .. 0. 118 



Width below at the middle 0.011 



Depth of the inner face 0. 004 



Depth of the outer faco 0.011 



Length o.* the bases of five proximal teeth 0. 027 



Width of the tongue-shaped bone at the middle 0. 010 



Depth of the deutary 2 mm from the end 0.012 



From the Niobrara epoch of Trego County, Kansas. Discovered by 

 Prof. 13. F. Mudge, of the State Agricultural College of Kansas. 



Empo semianceps, Cope. 



Represented by numerous specimens of various individuals from the 

 Kansas chalk. These embrace all the cranial bones in a fragmentary condi- 

 tion, several vertebral columns, and scales. 



These belong to smaller individuals than those referred to the E. nepceolica. 

 Characters of the species are to be seen in the ^pterygoid and larger mandib- 

 ular teeth. The former are minute, and cover one side and margin of the 

 bone en brosse without larger series. The latter have a cutting-edge on the 

 posterior aspect of the apex as well as on the anterior. It extends but a 

 short distance, while the anterior rises near the base, and is strongly convex. 

 The tooth curves backward ; the base is round in section. The convex pos- 

 terior and inner faces are rather finely striate-grooved. The larger teeth of 

 the external series are convex on the inner face ; they are two-edged, and 

 slightly incurved. 



The outer face of the dentary bones is strongly longitudinally parallel- 

 sulcate. The inner face and the surfaces of all the other bones are minutely 

 striate, exactly as in some of the Mosasauroids. The anterior extremity of 

 the premaxillary is straight on one side, and obliquely beveled on the other 

 to an obtuse compressed apex. The bevel becomes subvertical posteriorly, 

 supporting teeth much as in E. nepmolica. Two of its anterior teeth are a 

 little larger than those that lollow. The supposed pharyngeal is narrowed to 

 30 c 



