More links and websites
Information on earthworms is included on this page from Massey University’s soil bugs site.
More suggestions and sources
Lee, K. E. The earthworm fauna of New Zealand. Department of Scientific and Industrial Research, Bulletin 130. Wellington: R. E. Owen, Government Printer, 1959.
Glasby, C. J., and others. 'Phylum Annelida: bristleworms, earthworms, leeches'. In The New Zealand inventory of biodiversity. Volume 1: Kingdom Animalia: Radiata, Lophotrochozoa, and Deuterostomia, edited by D. P. Gordon. Christchurch: Canterbury University Press, 2007.