STRATIGRAPHIC POSITION OF LANCE FORMATION 361 



is quite possible that the skull of the individual of which we secured 

 the vertebrae could be recovered by more extended excavation than 

 we were able to make with the implements at hand. 



Since, with the exception of their occurrence in the post-Lara- 

 mie formations of the Denver Basin, the remains of Triceratops 

 have never been found outside the Lance formation, the finding 

 of Triceratops at this point is of far-reaching importance. It 

 shows that not only are the beds containing them above more than 

 6,000 feet of "Laramie" rocks (the basal portion of which is almost 

 certainly of Fox Hills age), but also that they are separated from 

 the "Laramie" ("Lower Laramie ") by an unconformity, which, 

 according to Veatch, 1 is profound and has involved the removal 

 of perhaps as much as 20,000 feet of sediments. This would seem 

 effectively to dispose of the contention that the Lance formation 

 (" Ceratops beds") is the equivalent of the Laramie. 



The Lance formation — for such it must now be called— along 

 the North Platte River above (south of) the mouth of the Medicine 

 Bow, passes virtually without known stratigraphic break into 

 beds which some twenty-five miles to the south have yielded Fort 

 Union flora, thus showing the similarity of this section with all 

 other known sections in which both Lance formation and Fort 

 Union are present. 



About 25 feet below the horizon of the Triceratops vertebrae, 

 in the area under discussion, we collected the following species of 

 plants: 



Sabal grandifolia? Newb. 

 Populus amblyrhyncha Ward 

 Viburnum marginatum Lesq. 

 Sapindus sp. 



Sassafras? sp. (Same as an unnamed species from the "Ceratops beds" 

 of Converse County, Wyo.) 



The palm, which is identified with some doubt as Sabal grandi- 

 folia, has a longer rachis than is usual in this species but is other- 

 wise indistinguishable. It was described originally from the 

 Fort Union near the mouth of the Yellowstone, and has been found 

 subsequently at many localities in Montana, Wyoming, and Colo- 



*Am. Jour. Sri., XXIV (1907), 18. 



