Williston.J Cretaceous Fishes. 247 



the most common of all, and not infrequently it is represented 

 by many associated teeth. From the plates, and from East- 

 man's figures, it will be readily identified in all its forms. 



LAMNA. 



Teeth, except some of the hindmost ones, with a narrow, 

 compressed, conical cusp, with one or two pairs of small, pointed 

 denticles. 



Some of the following species may belong to Odontaspis, 

 which can hardly be distinguished by the teeth alone, differing 

 only in the relatively less high and less subulated character of 

 the anterior ones, and in the usually larger size of the lateral 

 denticles. 



Lamna appendiculata. Plate XXVI, figs. 3-3c; plate XXXI, figs. -17-49. 



Otodifs appendiculatus (Roemer) Agassiz, Poiss. Foss., in, p. 279, pi. 

 xxxii, ff. 1-25: Davis, Trans. Roy. Dubl. Soc, iv, p. 402, pi. xli, ff. 1-11. 



Lamna oppendiculata Woodward. Cat. Foss. Fishes Brit. Mus., i, p. 393; 

 Proc. Geol. Assoc, xin. p. 196: Williston, cf. cit. 37 — Senonian, Cenoma- 

 nian, Turoniau ( ? i, Danian of Europe, Niobrara of Kansas, and Green- 

 sand of New Jersey. 



"Teeth robust, with a thick root, having a much flattened 

 postero-inferior face, the nutritive foramen not in a groove. 

 Outer face slightly convex or flat, often with a few indefinite 

 vertical folds on the basal half ; inner side of crown markedly 

 convex, smooth ; cutting edges prominent ; a single pair of 

 lateral denticles, broad, but pointed. Anterior teeth narrow 

 and upright ; lateral teeth much inclined backward, the anterior 

 teeth much more arcuate and longer than the posterior ones." 8 



Several teeth from the Niobrara chalk agree sufficiently well 

 with the foregoing description, and especially with Woodward's 

 figures, to permit their allocation here. They are somewhat 

 broader than the specimens figured by Woodward. Two of the 

 specimens differ markedly from the others in having the base 

 Hatter and the roots much less prolonged downward, the notch 

 of the base shallower and shorter. Another tooth from the 

 base of the Benton, in the conglomerate containing the speci- 

 mens of Corax curvatus and Ptychodus janewayiL agrees well 



6. Woodward, I.e. 



