Williston.] Cretaceous Fishes. 243 



Ptychodus whippleyi. Plate XXIX, figs. 10-15. 



Ptychodus whippleyi Marcou, Geol. North Amei\, p. 33, pi. ix, f. 4 : Leidy, 

 Ext. Vert. Fauna, p. 300, pi. win, ff. 19, 20: J. S. Newberry, Rep. 

 Expl. Exp., p. 147. pi. in. f.2; Cope, Cret. Vert., p. 294: Williston, cf. cit. 

 34 — Cretaceous, Texas i Marcou, Leidy); Kansas, Arkansas Valley (Cope): 

 Colorado, New Mexico. 



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

 ceived from Mr. Frank Springer, collected in the vicinity of 

 Las Vegas, in New Mexico, agree with the descriptions and fig- 

 ures 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 determination and locality are correct the species 

 must be referred to the Benton of Kansas, since the Niobrara 

 does not occur in the Arkansas valley. A single specimen from 

 the Benton of Kansas in the museum, without definite locality, 

 seems to agree pretty well with the Texas specimens, but the 

 specimen is an uncharacteristic one and may pertain to some 

 other species. 



Some of the teeth referred to this species show a marked re- 

 semblance to those figured by Woodward 3 (P. rugosus) , and by 

 Dixon | P. altior Dix. i 



The European species is described as having the sides of the 

 median elevation of the crown smooth, which is not the case 

 with the present species, the grooves continuing midway into 

 the lateral granulation.-. 



b ' 



Ptychodus, sp. Plate XXIX. figs. 2. 3; plate XXXI, fig. r>3. 



Ptychodus, sp., Williston. cf. cit. 34. 



Four teeth of moderately large size, from the Benton Creta- 

 ceous, of Salt creek, Russell county, and two others of smaller 

 size, also from the Benton, seem to belong to a species distinct 

 from any hitherto known. The larger ones will be distinguished 

 from those referred to the upper series of P. martini, which are 

 of nearly the same size and shape, by the smaller area of trans- 

 verse ridges, and the much larger area of marginal reticula- 

 tions, which are coarser. The teetli are more nearly square and 

 the convexity of the crown is greater. The two teeth of smaller 



& Cat. Foes. Pishes Brit. Mus.. I. pi V, fig. 2. 



