The Woodpeckers are very widely distributed, being only absent from the Australian region beyond Celebes and Flores. They are most abundant in the Neotropical and Oriental regions, both of which possess a number of peculiar genera; while the other regions possess few or no peculiar forms, even the Ethiopian region having only three genera not found elsewhere. The soft-tailed Picumninæ inhabit the tropical regions only, _Picumnus_ being Neotropical, _Vivia_ and _Sasia_ Oriental, and _Verreauxia_ Ethiopian. _Picoides_, or _Apternus_, is an Arctic form peculiar to the Nearctic and Palæarctic regions. _Celeus_, _Chrysoptilus_, _Chloronerpes_, and some smaller genera, are Neotropical exclusively, and there are two peculiar forms in Cuba. _Yungipicus_, _Chrysocolaptes_, _Hemicercus_, _Mulleripicus_, _Brachypternus_, _Tiga_, and _Micropternus_, are the most important of the peculiar Oriental genera. _Dendropicus_ and _Geocolaptes_ are Ethiopian; but there are no woodpeckers in Madagascar. The Palæarctic woodpeckers belong to the genera _Picus_--which is widely distributed, _Gecinus_--which is an Oriental form, and _Dryocopus_--which is South American. Except _Picoides_, the Nearctic woodpeckers are mostly of Neotropical genera; but _Sphyrapicus_ and _Hylatomus_ are peculiar. The geological record is, as yet, almost silent as to this family; but remains doubtfully referred to it have been found in the Miocene of Europe and the Eocene of the United States. Yet the group is evidently one of very high antiquity, as is shown by {303}its extreme isolation, its great specialization of structure, its abundant generic forms, and its wide distribution. It originated, probably, in Central Asia, and passed through, the Nearctic region to South America, in whose rich and varied forests it found the conditions for rapid development, and for the specialization of the many generic forms now found there. A large number of genera have been established by various authors, but their limitations and affinities are not very well made out. Those which seem best established are the following:--