For more than fifty years geologists have been describing unmistakable late Paleozoic glacial deposits, and during the past thirty years this knowledge has become generally acceptable, but unfortunately there is as yet no agreement as to whether this ice-age took place in late Upper Carboniferous time or wholly in the Permian. Among the textbooks we find the leading French writers placing the time of this glaciation in the late Upper Carboniferous, whereas those of Germany always refer the ice-age to the Permian, some without doubt, like Frech (1901), who says it is “unmistakably of early Permian time,” and others, like Kayser (1923) and Schaffer (1924), who consider it as of probable Permian age. Most of the American textbooks are for a Permian reference. Scott (1907) says: “The earliest Permian in the southern hemisphere was a time of vast glaciation,” and Schuchert (1924) placed the ice-age well up in the . . .