ITS" Cincinnati Society of Natural History. 



age. There is, tben, no alternative but to accept the result that a 

 Tertiary flora was contemporaneous with a Cretaceous fauna, estab- 

 lishing an uninteiTupted succession af life across what is generally 

 regarded as one of the greatest breaks in geologic time. 



He described, from the Niobrara Group, of Colorado, Syl- 

 XcBmus latifrons ; from the Fort Benton Group, two miles west 

 of Sibley, Kansas, Pelycorapis varius; from the Niobrara Group 

 or yellow ehalk, near the Solomon river, Kansas, Porfheus arcuatus^ 

 P. mudgei, and Fachyrhizodus leptopsis; from Ellis county^ Kansas, 

 Lamna macrorhiza, L. mudgei, and Empo merrilli; from Trego 

 county, Empo contracta and Empo semianceps; from the neighbor- 

 hood of Fort Wallace, Phasganodus carinatus, P. gladiolus, P. anceps; 

 from Phillips county, Tetheodiis pephredo; from Kansas, Enchodus 

 doUchus, E. petrosus, Pelecopterus ckirurgus, Toxochelys serrifer; 

 from Stockton, Kansas, Ptychodus janewayi; from Spring creek, in 

 Rooks county, Pelecoj^terus perniciosus; from the Greensand of 

 New Jerse}^ Osteopygis erosus, Enchodus oxytomus, E. tetraecus, Lep~ 

 tomylus forfex, Diphrissa latidens, Bryactinus amorphus, Ischyodus 

 stenohryus, I. tripartitus, I. longirostris, I. incrassatus, I. gaskilli, I, 

 fec^iiidus, Isotcenia neocaisariensis. 



And he furnished a section of the Cretaceous rocks of the region 

 west of the SieiTa Madi-e range of New Mexico as follows:* 



Dakota Group, 500 feet. 



Fort Benton Group, 2,000 feet. 



Niobrara Group, 400 feet. 



Fort Pierre Group, 1,500 feet. 



Uncertain (concealed in the Sag'e plain), 500 feet. 



G. K. Gilbertf found a section of the Cretaceous exposed by the 

 north fork of the Virgin river, from the vicinity of Mountain Lakelet 

 to Rockville, Southern Utah, 1,800 feet in thickness, and another on 

 the west fork of Paria creek, 935 feet. 



Prof. G. F. Credner+ described, from the Cretaceous of Texas, Salenia 

 texana. 



J. J. Stephenson § found the Cretaceous out-crop practically 

 unbroken from Golden, Colorado, to Mexico. On the west side of the 

 front or eastern range, there is a narrow area, of which only isolated 

 portions remain in Huerfano, Wet mountain. Current creek, and South 



''Proc. Acad. Nat, Sci. 

 t Geo. Sur. W. lOOtli Meridian, vol. 3. 

 X Zeitschrift fur d. gesammten Naturwiss. 

 § Geo. Sur. \V. 100th Meridian, vol. 3. 



