room tunnels. Some of the smooth surfaced slabs show current washings. The quartzites Ravensmo thinks may be some other age than the limestones. While I did not see the actual contact between the two series, yet I was within 3 feet of actual contact, and get this is not the slightest evidence to separate the two series (Later, I do not think this is Ravensmo's idea). The fauna of the limestones looks to me very much like the Llans Cambrian that formed up in Walcott about 30 years ago. It is therefore all Upper Cambrian or Ordovician, and more probably the same sequence down a few years ago in the Grand Canyon—the Tonto series (Tapeats m., Bright Angel Shale, Muav Li.). The Cambrian appears to end with reddish granular limestones, that also abound in trilobite fragments. Then follows either a thin quartzite or this green is in thick redded magnesians.