The puisars MP 0031 and CP 1919 exhibit periodicities in pulse intensity of approximately 2 and 6 min, respectively. In each pulsar strong bursts of puises are often followed by one or more similar bursts spaced at the appropriate 2- or omin period. Sometimes there is more than one burst per 2- or Omin period, and this combination of bursts then repeats as a unit until the component bursts independently diminish. These long "circuiation periods" are approximately equal to the time required for the marching subpuises observed in each pulsar to march one fundamental pulsar period. Radio-emission models involving plasma waves circling around pulsars are favored by these resuits.