The collection of Cetoniid Coleoptera in the Rijksmuseum van Natuurlijke Historie at Leiden contains, next to the usual assortment of chafers from various sources, several collections made by well-known specialists. Most important is the one made by F. T. Valck Lucassen (including the collection of O. E. Janson), acquired by the museum in 1940. A world collection of Cetoniidae is being arranged on the basis of this Valck Lucassen material. In 1928, the collection of G. van Roon was bequeathed to the museum, where it is to remain as such, not incorporated in the main collection. The data of the collection will be presented in this and forthcoming parts of a catalogue, accompanied by such revisional notes which it seems desirable to publish. Reference is here made to Junk's Coleopterorum Catalogus (Schenkling, 1921); in general, citations given by Schenkling will not be repeated in this series. Acknowledgements Thanks are due to the following persons, who communicated data or gave specimens in loan, from the collections under their care viz., Dr. C. A. W. Jeekel, Zoölogisch Museum, Amsterdam; Messrs. R. D. Pope and M. E. Bacchus, British Museum (Natural History), London; Dr. H. Roer, Zoologisches Forschungsinstitut und Museum Alexander Koenig, Bonn; Dr. G. Scherer, Museum G. Frey, Tutzing bei München. Goliathus Lamarck, sensu lato There is some confusion over the classification of the African Cetoniidae belonging to, or related to Goliathus Lamarck, due to extreme splitting and to inadequate knowledge of the correlation of the sexes. For the eleven species and three subspecies recognized here, there are