Examination of the density field suggests that the large-scale anticyclonic gyre generally supposed to obtain within the upper waters of the North Atlantic Ocean is considerably altered at middepths. Not only is there a strong return flow westward just south and east of the Gulf Stream-North Atlantic Current, but this return flow also turns southward near 30¿N and continues eastward all across the Atlantic. The warm and saline waters of the outflow from the Mediterranean Sea join the westward return flow south of the Gulf Stream-North Atlantic Current and are carried westward as they spread and mix, providing the great wedge of warm, saline waters found from 600 to 2500 m in the North Atlantic.