1. The "Park City formation" as defined by Boutwell is not a valid stratigraphic unit and the name should be abandoned.

2. Richards and Mansfield's terminology for the middle and upper members of the "Park City formation" may be extended from southeastern Idaho, these members constituting the Phosphoria formation.

3. The two members of the Phosphoria formation may be recognized as far toward the southeast as Ashley Creek, and the names Rex member and phosphatic shale member may be applied to them.

4. The phosphatic shale member contains no phosphate rock of commercial value, at least according to present-day standards, between Midway and Whiterocks River.

5. The Rex member east of the Duchesne River is found to interfinger with, and to be replaced by, "red beds" for which the name Mackentire "red-beds" tongue of the Phosphoria formation is proposed.

6. The lower member of the "Park City formation" thins eastward on the south flank of the Uinta Mountains and disappears beyond the Duchesne River. Eastward on the north flank it thickens, at least to the vicinity of Holiday Park, and its limestone content increases greatly.

7. The exact relationship of the lower member of the "Park City formation" to the Weber formation is not known because of the lack of data and a conflict in the observations already made. On the basis of essential lithologic character the writer is inclined to believe this lower member is merely a lithologic facies of the Weber formation. It may become the "Park City member of the Weber formation."