The New Zealand flatworm, Arthurdendyus triangulatus (formerly Artioposthia triangulata) has become established in the British Isles and the Faroe Islands and its human-mediated spread within Northern Ireland and Scotland is well documented. The geographical distributions within New Zealand of it and two related species, A. australis and A. testacea have always been assumed to reflect the natural distribution patterns.
The distribution of the indigenous New Zealand megascolecid earthworm Octochaetus multiporus (Beddard) in hill pastures of different fertilities in the southern North Island of New Zealand, and the population density throughout a year are described. Octochaetus multiporus was most numerous in soils of low to moderate fertility. High fertility soils had a similar population density to that of an adjacent area of native forest, indicating that the exotic pasture environment can favour Octochaetus multiporus in some circumstances.