88 KANSAS UNIVERSITY SCIENCE BULLETIN. 



ternal surface. The supraclavicle (sd) has about the same 

 proportions as that of Enchodus petrosus (pi. V, scls) . Figure 

 4 shows the fragments of the articular and the caudal ramus of 

 the dentary in position. The broken lines indicate the outlines 

 of the missing portions as represented in the impressions in 

 the matrix. The dorsal ramus is narrow and quite stout. This 

 portion does not send ventrally a thin plate of bone, but is dis- 

 tinctly rounded on the ventral edge, which definitely distin- 

 guishes this species from Enchodus ipetrosus Cope and En- 

 chodus dims Leidy. The following measurements indicate its 

 large size : 



mm. 



Length of supraclavicle 150 



Length of mandible (estimated) 300 



Depth of caudal end of mandible 73 



Encliotlus dims Leidy. 



This species was first described in 1857. The type specimen 

 is a portion of a dentary. A dentary, specimen No. 322 of this 

 museum, was assigned to this species by Stewart (Stewart, 

 1900). This specimen, though possessing the characters of 

 the type, seems to belong to another species. The characters of 

 the Stewart specimen are : base of dentary fang enlarged ; 

 cutting edge begins cephalo-externally at the base, but passes to 

 the front side by the time it has reached the extremity of the 

 fang; mesio-caudal surface rounded and distinctly striated; 

 cross section at the middle point is pyriform ; foramen for the 

 blood vessels supplying the fang at the ventral edge of the 

 mesial side of the base; the teeth caudad to the fang slightly 

 striate mesially; they are laterally compressed. A line drawn 

 in the long axis of the cross section of any of these teeth would 

 pass external to the fang. The external surface of the dentary 

 has prominent ridges radiating from the symphysis. This last 

 character was not mentioned by Stewart, and it seems not to 

 have been a character of Enchodus dims Leidy. It seems that 

 all of these characters except the last should be retained for 

 E. dims, but since this dentary can not be distinguished from 

 the dentary of specimen No. 803 (pi. Ill, fig. 9), which has 

 fangs like the specimen (No. 198 of the American Museum), 

 described by Hay as Enchodus sievus (Hay, 1903) , it will be re- 

 ferred to the species to which that specimen belongs. Another 

 specimen (No. 86 of this museum), a palatine complete with 

 its fang, described and figured by Stewart as Enchodus doli- 



