An electron conic has been reported from low-altitude particle observations of Dynamics Explorer 2 (DE 2). It has been suggested that the source of the electron conic is an oscillating parallel electric field, perhaps associated with an inertial Alfv¿n wave. We report here on electric field observations made at midaltitude by Dynamics Explorer 1 and at low altitude by DE 2 during the same time as the electron conic observations of Burch [1995>. We find evidence for oscillations of E∥ with frequency f~0.5 Hz, in agreement with the model of electron conics presented by Thompson and Lysak. However, there are discrepancies in the measured values of E∥/E⊥ and B/E compared with those expected for Alfv¿n waves. We believe these discrepancies may be due to nonlinear effects. ¿ 1998 American Geophysical Union