GREEN: ENCHODUS IN KANSAS MUSEUM. 75 



than the length of the mandible, and the depth of the caudal 

 end of the skull somewhat less than the length of the mandible. 

 (See pi. VI, figs. 3 and 4, and pi. XI, figs. 1 and 2.) The head 

 was very large in comparison with the body; hence the fish 

 could not have been a rapid swimmer. The nature of the 

 teeth would indicate that it was a predatory fish, and the fact 

 that of the sixty palatines in the collection only one (pi. XV, 

 fig. 14) shows a new palatine fang replacing the old, would 

 point to the conclusion that Enchodiis either had few enemies 

 or was very successful in defending itself. Otherwise, it 

 seems, of the forty individuals represented by these sixty 

 fangs, some would have met their death at a time when the new 

 fang had not yet completed its growth. The fangs of both 

 palatine and dentary are well suited to a voracious fish, the 

 palatine fangs being directed cephalo-ventrally at nearly 45 

 degrees (pi. V, pal, and pi. VI, fig. 3) and all of the teeth very 

 sharp. The palatine bears a deep groove on the mesio-dorsal 

 surface (pi. II, fig. 1, paid) for the reception of the lateral 

 processes of the ethmoid. These two elements were found in 

 position in Enchodus petrosus, specimen No. 836 (pi. IV, pal, 

 eth) , and are so shown in No. 198 of the American Museum 

 (pis. VIII and IX). The relation of the palatine to the frontal 

 is also shown in the same plate (pal and /r) , and in Enchodus 

 2}etros2is, specimen No. 807, plate V. In the case of specimen 

 No. 836, plate IV, the ventral surfaces of the right palatine and 

 frontal are shown, while in plate V the dorsal surfaces of the 

 left frontal and palatine of the same species are figured. 



The palatine is developed in a very unique manner. Numer- 

 ous writers have discussed the nature of the swollen portion 

 of this bone and have expressed various opinions concerning 

 it; Doctor Loomis (1900) described it as a mass of osteoden- 

 tine, while Doctor Hay (1903) says that he regards it as 

 "merely very compact bone." Because of these varying and, 

 in this instance, diverse opinions, it has seemed advisable to 

 examine this bone in detail. The results display some very 

 interesting facts. The palatine is quite hard, but may be very 

 easily ground on an emery wheel. Several of the large pala- 

 tines of Enchodus petrosus Cope were used in the investi- 

 gation. A ventral view of the palatine shows the series of 

 crescentic scars external to the large ventral keel. The keel 

 is well shown in plate VII, figure 15. About the center of each 



