Two instruments at Siple Station, Antarctica have provided additional evidence of the generation of 1 Hz hydromagnetic waves in the magnetosphere. The waves result from ion cyclotron interaction with positive ions on L=4 field lines near the equator. In a previous report we presented one event, August 1, 1977, where structured Pc 1 hydromagnetic pulsations, pearls, were accompanied by delayed optical pulsations with the same repetition rate. By using the observed wave frequency, pulsation repetition rate, optical pulsation delay time, and calculations employing model plasma parameters we were able to show the waves could be due to tens of keV energy O+ or He+ ions or to MeV protons. Two additional events, August 4, 1977 and May 29, 1978, have now been analyzed. These events, using the same model parameters, are consistent with tens of keV energy protons, more plentiful in the ring current than MeV protons, as well as tens of keV O+ and He+. The wave/particle interpretation has been compared with the availability of energetic positive ions, with expected generation close to the plasmapause, and with theoretical predictions of wave frequency and growth rate. The comparison is favorable in each case to our interpretation. A few inconsistencies are also examined, the location of all of the proton interaction regions north of the equator, for example, and a modification of our original model is proposed.