The Origin and Migrations of Australasian Echinoderm Faunas Since the Mesozoic H. Barraclough Fell, Victoria University College, Wellington, New Zealand. [Read before the Wellington Branch, August 14,1952; received by Editor, September 10, 1952.] Contents 1. The Generic Content of the Tertiary Echinoderm Faunas of Australasia. 2. The Origins of the Australasian Tertiary Echinoderm Faunas. 3. Tertiary Faunal Migration Routes to Australasia. 4. Faunal Migration Between New Zealand and South America. 5. Trans-Tasman Faunal Migration. Summary and References. Abstract Similarities in the Tertiary echinoderm faunas of New Zealand and Australia are such as to indicate a common origin from the northern Indo-Pacific. Southward migration probably has occurred along the Indo-Malayan archipelago, or its Tertiary equivalents; but northward movements of Australasian genera into the Indo-Pacific can be detected from the Miocene onward. In the late Tertiary a west to east trans-Tasman faunal migration can be detected. Such similarities as exist between the echinoderm faunas of New Zealand and South America are probably a result of faunal contributions from the former to the latter. Possible mechanisms enabling faunal migration of echinoderms are considered. The aim of this paper is to examine the general character and the generic content of the echinoderm faunas of Australia and New Zealand since the close of the Mesozoic; and also to offer a tentative interpretation of the data so far as they bear upon the problem of the origins of the faunas, and their migration routes into, out of, and within the Australasian region. Finlay's trans-Tasman correlations of 1947 are employed. The New Zealand palaeontological evidence is mainly based on unpublished studies still in progress. I am indebted to Dr. J. Marwick, to the late Dr. J. M. Finlay and to Dr. C. A. Fleming, all of the Geological Survey of New Zealand, for age determinations of the New Zealand material. The Australian records are taken mainly from the literature, and as far as possible their age-determinations have been revised in accordance with Finlay's views. In this I have had the assistance of Dr. J. Marwick. The generic placing of some of the material from Australia differs from that assigned to it in the older literature, and is more in accord with current ideas. The reasons for the changes will be given in a later publication. I am indebted to the Director of the National Museum of Victoria for the opportunity to examine fossils, and to others who have sent Australian specimens. 1. The Generic Content of the Tertiary Echinoderm Faunas of Australasia (a) Early Tertiary. Our knowledge of the Australasian echinoid faunas of the Cretaceous and Eocene is very fragmentary. In New Zealand occurred the Cretaceous Micraster,