ene poet 
Marcou’s Geological Map of the United States. 387 
Wislizenus and others along the valley of the Canadian river 
not far from Pyramid Mount, where the Gryphea was pr Z 
Farther east on the False Washita and near the Canadian, the 
Cretaceous fossil Gryphea Pitchert occurs in abundance and near 
the great beds of gypsum. Leon Spring, in the southern part of 
the Llano, has afforded abundance of Cretaceous fossils, and thi 
place is represented on the map as Jurassic. Cretaceous fossils 
were also obtained by Capt. Pope from the bluffs of the Llano 
at the Sulphur Springs of the Colorado and from the surface of 
the plateau near the Sand Hills.* The Llano of Texas is well 
known and is undoubtedly the continuation of the Llano Esta- 
cado. The bluffs are filled with Cretaceous fossils already de- 
alley of the Rio Grande. The same alternative is presented to 
us along the Upper Missouri; the highest table-land 1s colored as 
But the most striking feature of the map remains to be no- 
ticed. We find an area equal to that of all the States east of the 
Mississippi colored as Triassic. The section also represents this 
formation as enormously thick, and with four divisions corres- 
ponding to those in Europe. The color is extended on the map 
along the whole course of the Missouri down to Council Bluffs, 
to reach and bor- 
d 
been shown by Mr. Dawson to be 
