This part comprises a taxonomic revision of 29 Tonna-species and for other species of Tonnidae in the genera Eudolium and Malea. Tonna hawaiiensis is described new to science. The text gives a detailed description of the animals and shells as well as information on synonymy, distribution (with detailed maps) habitat and biology. As far as possible type material an large series of shells covering the whole species range were studies. Material from at least 29 museums was included in this monograph. The bibliography includes 173 references.
