1. Dual hemoglobins were isolated from both Lemmus and Discrostonyx, two genera of microtine rodents of the tribe Lemmini. 2. The dual hemoglobins result from dual alpha-chains and the charge difference Asp----Ala at position alpha 5. 3. The beta-chains of Dicrostonyx and Lemmus hemoglobins differ in charge by Ala----Asp at beta 125. 4. Cladograms are presented for the hemoglobin chains of microtine rodents.