WILLISTON : FISH TEETH FROM KANSAS CRETACEOUS. 33 



Pt}jcho(Jiis occidentalis. Plate XI, fig. 4; plate XII, fig. 13. 



P/i/chodus ocridpnfal'S Leidv, Proc. Acad. Nat. Sci. Phil. 1868, p. 207; Ext. 

 Vert. Fauna West. Terr. 308, pi. XVII, ft". 7, 8, XVIII, flf. 15-18: Cope, 

 Cret. Vert. 24'1 — Niobrara, Benton of Kansas. 



Two teeth, one from the same conglomerate that yielded the teeth 



referred to P.janewayii, the other, without locality, from Mr. Joseph 



Savage's collection, I refer to this species. The species differs from 



the following in having the transverse ridges continued to the lateral 



rims, and not separated by an area of fine reticulation. The anterior 



surface has finer, elongated, nearly straight ridges and grooves in this 



species, while in the others the markings are reticulate or vermicu- 



late. 



I'tt/chodus Jfuteirdijii. Plate XII, figs. 9, 10, 11. 



Sporetndu^ ianeivayil Cope, Hayden's Bull. U. S. Geol. Surv. No. 2, 1874. 



pi. XLVli. 

 Ptychodus janewaijii Cope, Cret. Vert. 214. 



" Surface irregularly convex, covered with a dense layer, which 

 does not exhibit pores, and is thrown into transverse or oblique 

 ridges. Surface with four folds, which traverse it obliquely from 

 border to border. At the base of the outer, at one end, is a series of 

 adherent tubercles ; at the basis of that, at the opposite end, is a 

 broken fold, with tubercles at its outer base. Length 0.0045 m., 

 width 0.0025 m. A portion of a larger and more central tooth has the 

 surface with an unsymmetrical convexity, and is crossed transversely 

 by five folds, from border to border." Cope, 1. c. 



Three small teeth, shown enlarged in pi. XII, ff. 9-11, from the 

 conglomerate containing specimens of Corax curvatus, ap^Dear to be- 

 long to this species. The horizon of the conglomerate is near the 

 line of contact between the Dakota and Benton, in Ellsworth county. 

 Cope's type was from a bed of conglomerate containing Lamna and 

 O.ryrhina teeth of small size near Stockton. It is probable that the 

 horizon is the same in both. 



Ptijchodiis trhippleiji. Plate XI, figs. 10-15. 



Ptychodua ichlppleyi Marcou, Geol. North Amer. HH. .33, pi. IX, f. 4: Leidv, 

 Extinct Vert. Fauna, 300, pi. XVIII, ff. 19, 20: J. S. Newberry, Rep. Expl. 

 Exp. 147, pi. Ill, f. 2: Cope, Cret. Vert. 294 — Cretaceous, Texas (Marcou, 

 Leidy); Kansas, Arkansas Valley (Cope); Colorado, New Mexico. 



Thirteen teeth from Dallas, Tex., and a number of others received 

 from Mr Frank Springer, collected in the vicinity of Las Vegas, in 

 New Mexico, agree well with the descriptions and figures of this 

 species, as given by Leidy. The same species has been referred to 

 the Niobrara chalk of the Arkansas valley by Cope. If his determi- 

 nation and locality are correct the species must be referred to the 

 Benton of Kansas, since the Niobrara does not occur in the Arkan- 

 sas valley. A single sj^ecimen from the Benton of Kansas in the 



3— K.U.Qr. A— ix 1 



