The millipeds of Panama (Diplopoda)

ing in Panama for original collecting, with habitats ranging from tropical lowlands to mountains as high as 11,000 feet, and ecological situations varying from semi-desert to extreme rain-forest, contains several times the number of milliped species presently recorded.Difficulties encountered in the past in studying Panama millipeds include widely scattered and often inadequate descriptions; lack of illustrations of essential structural parts; indefinite locality records; few keys to any of the groups involved; and type specimens difficult of access in private collections, scattered through many museums, often misplaced, or even no longer in existence.To overcome some of these difficulties for future workers, in addition to describing and illustrating the new species in this paper, accepted species, previously reported, are listed with citations, and keys having application only to Panamanian taxonomic groups are presented.With the large amount of material available, both in the present collection and others that I have seen before, it is now possible to propose settlement, in various ways, of some of the identification problems involving already published species; others remain a challenge.Unless otherwise stated in the legends for the figures, all drawings were made from the holotype specimen from which most characters included in the descriptions also were derived.Where detailed collection data are given for any of the species, i.e., locality, date, ele- vation, and details of collection, as "Berlese" or "(B-638) forest floor litter," Dybas was the collector if another person is not named.All holotype specimens, with one exception mentioned in the text, are deposited in Chicago Natural History Museum.Where available, a paratype specimen of each species has been deposited in the United States National Museum.All other specimens have been returned to the former museum.Grateful acknowledgment is