58 WILLIS T. LEE 
stratigraphic position, and general appearance, the Galisteo forma- 
tion is here regarded as probably a time equivalent of the Triceratops 
or late Cretaceous red beds of the Elephant Butte region. 
In concluding I would emphasize the fact that there are two red 
formations in the Rio Grande region, which resemble each other so 
closely in places that careful observation is sometimes necessary in 
order to distinguish between them; and that neither of these forma- 
tions belongs to the Jura-Trias or Permian, to which they have 
frequently been referred, the older one belonging to the Pennsylvanian 
system, and the younger one to the Upper Cretaceous. 
U. S. GEOLOGICAL SURVEY, WASHINGTON, D. C., 
June 28, 1906 
