New evidence regarding the age of the San Andres formation is presented, and it is correlated with the Cherry Canyon formation of the Delaware Mountains, the upper part of the Word formation of the Glass Mountains, and the "Blaine of Texas" of the Eastern shelf. The Glorieta formation of New Mexico is correlated with the upper part of the Cutoff member of the Bone Spring formation of the Delaware Mountains, the uppermost beds of the Leonard formation of the Glass Mountains, and the "Holt pay" of north-central Ector County, Texas. The San Angelo formation is correlated witb the upper part of the Yeso formation of New Mexico, with beds in the upper part of the Leonard formation of the Glass Mountains, and with the middle and lower parts of the Cutoff member of the Bone Spri g formation. The Grayburg formation of the subsurface is shown to be equivalent to the lower part of the Queen formation of the Guadalupe Mountains.