Last year our Museum received a very large earthworm, collected in Brazil by Mr. H. du Dréneuf. I believe the specimen must be identified with Anteus gigas, though it does not agree in all its characters with the description given by Perrier of this species ¹). This description was based upon two specimens, one from Cayenne, the other from an unknown locality. Although our worm is not in a very good state of preservation, so that some interesting points of its organisation remained unknown to me, my examination has enabled me to add something to our rather scanty knowledge of this species, and to come to a certain conclusion about the question of its supposed identity with Microchaeta rappi. Vaillant ²) pointed out that, according to Perrier’s description, Anteus gigas agrees in many respects, i.e. the arrangement of the setae, the indistinctness of the clitellum, the thick anterior septa, the shape of the nephridia, with Microchaeta rappi from the Cape, afterwards described by Beddard ¹) and Benham ²). Though Benham seems to be disposed to join Vaillant’s suggestion, he has ranged in his Classification of Earthworms ³) the genus Anteus among the Lumbricidae incertae sedis and concludes his description of this worm with the remark: »it would be exceedingly interesting to investigate more fully the anatomy of Anteus, for its locality, Cayenne, is so far removed from the home of Microchaeta in South Africa, that it seems scarcely credible that the two are identical.”