96 KANSAS UNIVERSITY SCIENCE BULLETIN. 



No. 1837, and Enchodus gladiolus Cope, No. 1818, all three of 

 which are in the American Museum, I am convinced that they 

 are of one species. The only definite point of difference that 

 can be observed is the more prominent grooving of the pala- 

 tine fang of the Enchodus gladiolus specimen. That such a 

 character as this does not merit so much consideration is proved 

 by the fact that equally as great variations as these are con- 

 stantly met with in the study of the other specimens. The two 

 large palatine fangs represented in plate III, figure 1, are from 

 different specimens of the same species but the grooves on the 

 right palatine are very prominent while those on the left 

 palatine are very low and broad. They have all the appearance 

 of having been worn down. The compression in each of the 

 fangs is identical, being much the same as in the American 

 Museum specimen. No. 198, described as Enchodus sievus by 

 Doctor Hay (Hay, 1903). Such differences as these may be 

 explained in part by the difference in the age of the individuals, 

 but probably to a greater degree by the difference in the age 

 of the teeth. Aside from this, there is great normal variation 

 observable in the genus which is assignable to no definite cause. 

 An illustration of this is to be seen in the pair of fangs re- 

 ferred to. The left palatine (upper figure) has two distinct 

 grooves on the mesio-dorsal surface, the caudal one of which 

 is for the articulation of the ethmoid. The two grooves ar^' 

 separated by a ridge of bone (r). No such ridge occurs in th.' 

 right palatine (lower figure) , and the groove is as large as thai 

 of the left bone would be if the ridge were not present. Such 

 dissimilarities are frequent even in paired bones. In plate III, 

 figure 2, there is to be seen a depression on the cephalic end of 

 the right palatine just above the base of the fang. It could 

 not be determined to which species several of the specimens in 

 this collection belong on a basis of the grooves on the palatine 

 fangs, as this character varies from almost imperceptible 

 striations to grooves as distinct as those found on the palatine 

 fang of the specimen of Enchodus gladiolus, No. 1818, of the 

 American Museum. This diflference alone is wholly insufficient 

 as a specific character. 



The best specimen of Enchodus dolichus in the collection is 

 No. 814, figured in plate XI. It consists of a very complete 

 skull with six vertebrae attached, and a fine pair of pectoral 

 fins. The dorsal surface of the skull is so much like that of 



