In 1960 and again in 1961 a small collection of live fern rhizomes was sent to Kew by Dr. R. Leveque from the main island of the Galapagos group as an experiment in air transport of live plants from these islands. The purpose of this exercise was to establish the feasibility of extending the cytological work now in progress on many temperate and tropical fern floras to an area of exceptional biosystematic interest. The experiment was successful and the help of Mr. H. Bruty, Foreman of the Ferneries at Kew, is gratefully acknowledged. Few plants died, either in transit or subsequently, and in many species several specimens survived. No species represented in either consignment was in fact lost before cytological observations had been completed on it. The cytological work, using standard techniques developed for this type of material (for further details see Manton, 1950; Roy & Manton, 1965) has been carried out in Leeds on material fixed at Kew as opportunity offered between 1961 and 1966. The naming of the specimens on the other hand has taken place at Kew with little or no assistance from the Leeds contributors. That the combined results are fragmentary is inherent in the experimental nature of the enterprise. Nevertheless, they show that this type of study is both possible and rewarding and, in view of the exceptional phytogeographical interest of the area, it is greatly to be hoped that some opportunity will be found for its extension. A list of the species examined, with a summary of the cytological findings, is given in Table I. Voucher specimens of all the taxa are deposited at Kew. The taxonomic notes which follow amplify the information relevant to the worked specimens by indicating areas of profitable further enquiry. For ease of reference the genera, but not the species, are numbered and arranged alphabetically.