92 KANSAS UNIVERSITY SCIENCE BULLETIN. 



mens at hand indicate, could easily fall within the limits of 

 normal variation. The contour of the skull, as indicated by 

 line c-c, taken at the line s-s, is very similar to the contour of 

 Enchodus dolichiis, at the same place (pi. XI, fig. 1). The ab- 

 sence of the minute fringe of teeth on the external alveolar 

 border of the dentary is the definite character which separates 

 this species from Enchodus dolichus and Enchodus shumardi. 

 It is about the size of the former, and the skull is about twice 

 the length of the skull of the best specimen of Enchodus 

 sliumardi (pi. XV, fig. 1). The palatines are very nearly in 

 position, but the fangs are turned outward. Both display the 

 mesial aspect. The deep groove in which the ethmoid (eth) 

 articulates is shown in the right palatine just cephalad to the 

 letters pal. It runs very nearly parallel to the ventral sur- 

 face of the palatine, and its cephalic end is in line with the 

 palatine fang. This groove and its fellow of the opposite 

 bone receive the short lateral processes on the cephalic end of 

 the ethmoid. The latter is complete in this specimen and is 

 represented in the figure. The relation of the ethmoid to the 

 palatines is better understood from inspection of plate VIII, 

 where a dorsal view of the corresponding elements of one of 

 the larger species is represented. This figure shows these 

 bones in position. The left palatine of the cotype of 

 E. amicrodus has the fang broken off at the middle. This pala- 

 tine is attached to the pterygoid caudally. The palatine fangs 

 are very straight, slender, and fluted mesio-caudally. They 

 are compressed laterally, with a cutting edge in front. The 

 short cephalo-dorsal processes over the bases of the palatines 

 are at unequal distances from the base of the fangs, the 

 process on the right palatine being four millimeters and that 

 on the left palatine six millimeters from the base of the fang. 

 The dentary fang is distinctly grooved mesially. The other 

 teeth are only slightly grooved on this surface. The pterygoid 

 teeth have their external surfaces slightly striated. The den- 

 tary is marked externally with definite rows of small tu- 

 bercles, which radiate from the symphysis. That the sym- 

 physial portion of the dentary was tuberculated also is shown 

 by the impression of the left dentary in the matrix. The 

 metapterygoid and mesopterygoid are both represented. The 

 right metapterygoid is complete but not in position. The left 

 metapterygoid, which was exposed to view by removing a por- 



