Acknowledgements

The authors wish to gratefully acknowledge the help given by the Internal Research Committee of the Victoria University of Wellington by a grant in aid of technical assistance for the 1961-1963 collection series; to Professor L. R. Richardson for his helpful advice during the 1961-63 collection series, and to Mrs. Helen Elliott and Mr. R. Buddle for efficiently processing and recording the data from this collection series; to Professor J. T. Salmon and Professor J. A. F. Garrick for helpful discussion; to Mr. H. S. Roberts of the Applied Mathematics Division of the Department of page 21 Scientific and Industrial Research for assistance with the statistical analysis of data, and to Mr. M. M. Loper, Technical Officer of the Zoology Department, V.U.W., for photographing the specimens.