There are no published records of the occurrence of Acanthocephala in the vertebrates of Japan. Professor Seitaro Goto has very kindly sent me a small collection of these worms for identification. While the collection is not extensive, it seems worth while to publish the results of the investigation, especially since there are several new species and a considerable amount of new biological data. In the ten vials of materials contained in this consignment, but seven host species are represented. Four of these are amphibians, two are fishes, and one is a whale. The parasites which these harboured include four new species of the genus Acanthocephalus, a previously undescribed member of the genus Arhythmorhynchus, a species of the genus Echinorhynchus and one unidentified species each in the genera Bolbosoma and Centrorhynchus.