The results reported form part of the series dealing with the timbers of the south-west Pacific area and cover 32 genera of the Myrtaceae. The timbers of this family are perhaps more important, from an economic standpoint, than those of any other in the area under consideration (with the possible exception of the Dipterocarpaceae). Based on the examination of all available species, the anatomical features of each genus have been summarized and the results set out in tabular form. From these a grouping of the genera of the family has been made, which reveals one or two inconsistencies with the botanical classification as proposed by Niedenzu. Particular mention has been made of the anatomical variation in Eugenia (sens, lat.). The affinities of the described genera with those of the New World, and the anatomical differences between the Myrtaceae and the closely alIied Lecythidaceae, are discussed. Anatomical features separating the Myrtaceae from four other families with some similar features have been pointed out.