WILLISTON : FISH TEETH FROM KANSAS CRETACEOUS. 35 



Chiloscyllium Muller and Henle, Molasse; Crossorhinus Muller and 

 Henle, Gault; Oantioscylli H>n Woodw , Turonian ; G'mglymostoma 

 Miiller and Henle, Danaian, Eocene. 



Numerous teeth from the Lower Cretaceous of Kansas seem in all 

 probability to belong in this family, and agree pretty well, though 

 rather large, with the teeth of Scyllluni, to which I refer them pro- 

 visionally. 



Scj/lfiiim ruf/ostnit. n. sp. Plate VI, fig. 5. 



Central cusp broad, pointed, nearly symmetrical, the cutting edges 

 nearly straight, one of them a little longer than the other and slightly 

 convex near the tip : a single pair of lateral denticles, which are nearly 

 eqnilaterally triangular in shape ; principal cusp with six or seven 

 strong ridges on the basal two-fifths ; denticles with four or five simi- 

 lar ridges reaching two-thirds of the way to the apex ; root narrow, 

 apparently not at all produced at the angles ; thinned and not at all 

 tumid. 



Type No. 1949, U. S. National Museum, Greenleaf sandstone at 

 Greenleaf ranch. 



Height of middle cusp 7 mm. 



Width of same at base 4 " 



Height of denticles 3 " 



Width of same 2.2 " 



Sri/llium plauideits, n. sp. Plate VI, fig. 7. 



Central cusp broad, j)ointed, convex from .side to side, with sharp, 

 non-crenulate edges : lateral cusps sharply pointed, smooth, two in 

 number ; root thin, narrow, moderately produced below the posterior 

 denticle, smooth. 



Height of median cusp 4 mm. 



Width of same at base 3 " 



Width of base of tooth G " 



Height of denticles 1.] " 



Type No. 1949, U. S. National Museum. From same horizon as 

 the preceding species. 



I refer provisionally to this species numerous other specimens from 

 the same horizon and collection. They differ in the relative size of 

 the denticles, the more posterior direction of the main cu.sp, and the 

 size. One tooth seems to lack the anterior denticle, which is always 

 the smaller of the two ; its absence may be due to injury. 



Sci/Uinin (Lainiia ?) f/r<t<f/fs. u. sp. Plate VI, fig. G. 



Main cusp elongate, slender; inner surface smooth, gently convex 

 longitudinally, more so transversely, with sharp, smooth edges, the in- 

 terior edge nearly straight, the posterior somewhat concave ; denticles 



