In my description of this large earthworm from Borneo ¹) I made already the suggestion, that the species probably did not belong to the genus Moniligaster, but I preferred to range it provisionally in this genus till we were better informed about the characters of several Moniligaster- species, only briefly described by Bourne. Since this author published a detailed account of the anatomy of Moniligaster grandis and a dozen of other species of this genus, found in S. India. They all agree in the situation of the oviducal pores between segment XI and XII and in the structure of the prostata. There now remains for me no doubt, that the Borneo-worm, which differs not only by the position of its oviducal pores upon segment XIII, but also by having a totally different prostata, cannot belong to the genus Moniligaster, but must be ranged in an other genus, for which I propose the name of Polygaster. I think that the Moniligaster viridis from Serawak, afterwards described by Beddard in his Monograph of the Oligochaeta, p. 203, will prove to be identical with our Polygaster coeruleus.