green: ENCHODUS in KANSAS MUSEUM. 97 



Enchodiis amicrodus that without other elements present it 

 would be difficult to distinguish them (cf. pi. X, fig. 3). The 

 palatine fangs are not shown in the figure. They are covered 

 by the premaxillaries, but one fang may be seen in the speci- 

 men. It is broken near the middle, showing it to be laterally 

 compressed, with a cutting edge in front. The premaxillar>' 

 is well preserved. The alveolar border of it is three-fourths as 

 long as the alveolar border of the dentary. The premaxillary 

 teeth of this species are relatively more than twice as long 

 as those of Enchodus dims (cf. pi. VI, fig. 3) . The dentary 

 has a few ridges radiating from the symphysis; the articular 

 has numerous slightly tuberculated ridges radiating from the 

 cotylus. The minute teeth on the external alveolar border of 

 the dentary are one-half as long as the premaxillary teeth. 

 In this specimen this row of minute teeth on the dentary is 

 not interrupted as it passes the dental fang. The small teeth 

 on the symphysial portion of the dentary are broken off, but 

 their positions are easily determined by the bases, which are 

 plainly visible (fig. 1, den). This is true of the specimens 

 figured in plate XIII, figure 2; plate XIV, figure 2; and plate 

 XV, figure 10. But the dentary, No. 57, figured and described 

 by Stewart as Enchodus doUchus (Stewart, 1900), has no teeth 

 external to the base of the dental fang, there being a space of 

 five millimeters where there are no small teeth. The pair of 

 dentaries. No. 815, not figured, has two small teeth external 

 to the base of the left fang. Thus this character seems to be 

 subject to considerable variation in this species, and has little 

 or no value as a specific character. The opercular has many 

 large, irregular ridges radiating from the point of attachment 

 to the hyomandibular. These ridges become more regular, 

 smaller, and tuberculated, on their distal two-thirds. Nearly 

 the whole of the subopercular is covered with small, even-sized, 

 tuberculated ridges radiating from the point of attachment to 

 the opercular. These become less numerous, larger, and less 

 tuberculate near the dorsal and ventro-cephalic edges of the 

 bone. A small area, averaging five millimeters in width, along 

 the ventro-cephalic edge of the bone is smooth. The stout, 

 tapering bar on the mesial side of the opercular is shown in 

 figure 2. The epihyal (fig. 2, eh) is very thin at the cephalic 

 end, and thickens caudally. On the caudo-dorsal edge is a 

 knob for the articulation of the interhyal. This latter element 



