Cosmic ray particles with kinetic energies well below cutoff values were detected during a high-altitude balloon flight at 41'mDN geomagnetic. These particles had kinetic energies up to 400 MeV/amu and charges in the range 6?Z?30. They are probably reentrant albedo particles and are of interest primarily becuase they can be confused with fast, ultraheavy primary particles in some experiments.