Recently, it has been suggested that the plasma sheet extends far down the flanks of the magnetotail on closed field lines where viscous interaction plays a significant role in the maintenance of the plasma sheet. This configuration implies that in an open magnetosphere the X line in the tail is closest to the earth in the center of the tail, curves away from the earth toward the flanks of the tail, and fans into a broad sheet, a tangential discontinuity, which borders the flanks and connects to the day X line. The butterfly cross section of the plasma sheet is consistent with this model. A recent observation of the separatrix beyond the neutral point by the Apollo 16 subsatellite is inconclusive.