Observations on preparations of the toucan, Ramphastos toco, infected with Plasmodium huffi Muñiz, Soares and Batista indicated the possibility that this infection may have been a mixed one. The exoerythrocytic stages are predominantly of the elongatum-type. They are similar to P. elongatum in the spherical form and self-limitation in size of the schizonts. They differ from elongatum in producing a larger number of merozoites and in effecting abnormal changes in some infected host cells.