Introduction

In the course of a study of New Zealand eels, a small collection of eel larvae, about 20 specimens in number, was assembled from various sources in this country. During the early stages of identification and description of these specimens several large collections of leptocephali were made available to the author for study purposes from institutions outside New Zealand—namely, (a) the Centre d'Océanographie de l'Institut Française d'Océanie, Nouméa, New Caledonia, (b) the C.S.I.R.O. Division of Fisheries and Oceanography, Cronulla, New South Wales, (c) the Australian Museum, Sydney, and (d) the Western Australian Museum, Perth. At the time of writing the total number of leptocephali assembled by the author is about 1100 specimens. The present paper, however, deals with only a small fraction of this number, some 14 specimens, belonging to the genus Anguilla Shaw and referable to four or five of the six known Australasian species. This group of larvae was chosen for study before others because Anguilla, more than any other genus of eels, is the most completely known. Eel larvae are often difficult to identify, mainly due to insufficient knowledge of the adults. The species of Anguilla, however, have been so well described (Ege, 1939) from their adults and are so well characterised that the identification of their larvae is a relatively easy matter. Further, Jespersen's (1942) account of the larvae of the Indo-Pacific anguillid eels in the massive Dana collection (1500 specimens) serves as a most valuable reference in this present work.

The author would here like to express his warmest thanks to the authorities of the above institutions who kindly placed their collections on loan; to Mr M. Legand (I.F.O., Nouméa), Mr I. S. R. Munro (Div. Fish. Oceanogr., Cronulla), Mr G. P. Whitley (Australian Museum, Sydney) and Dr R. W. George (Western Australian Museum, Perth) without whose individual interest this study would not have been possible; finally, Prof. L. R. Richardson, of the Department of Zoology, Victoria University of Wellington, for his welcome criticisms.