A large part of the oil and gas produced in North America is obtained from Paleozoic rocks. All the geological conditions required for accumulation and production are present in the Paleozoic fields of the Mid-Continent and Appalachian provinces. In Europe, practically no Paleozoic oil is known, though the geologic sequence and history are so similar in the two continents that geologists commonly point out the comparability. The only real difference is a matter of overburden, or depth below the surface. In Europe, there is a very thick blanket of Mesozoic and Tertiary formations overlain by heavy glacial drift. Admitting the many problems of folding and unknown complications with depth, the writer believes that Paleozoic accumulations of petroleum may be expected in Europ .