The raccoons, genus Procyon, colloquially known as “coons,” belong to the carnivorous family Procyonidae, which also includes the American genera Nasua, Nasuella, Bassaricyon, and Potos, and the Old World genera Ailurus and Ailuropoda of the subfamily Ailurinae.

The members of the Procyon lotor group (subgenus Procyon), with a transcontinental range from southern Canada to Panama, except in parts of the Rocky Mountain region, and including those inhabiting several distant islands, are among the most familiar and characteristic of North American mammals. This group is not known to occur south of Panama. It is overlapped in the Isthmian region by the so-called crab-eating raccoons of the subgenus Euprocyon, which range from that northern limit as far south as Paraguay in South America. The raccoons have been greatly reduced in numbers or have disappeared in many formerly wooded sections, owing to clearing and intensive human occupation. Despite adverse conditions, however, they have maintained themselves in many places with remarkable tenacity. Trapping for other fur bearers may have reduced the northern fringe to some extent, but the general range of the group has been little diminished. At the present time raccoons reach their northern limit in regular occurrence on Vancouver Island, B. C.

The continental forms of the subgenus Procyon constitute a compact assemblage of closely allied geographic races all assignable to Procyon lotor. Complete intergradation is evident in numerous cases and the relative value and combination of characters presented indicate such close relationships that it can safely be assumed where lack of material leaves gaps in the known ranges.

In the present revision of the raccoons are treated the North American continental species as far as the eastern border of Panama and the species on outlying islands along both the Atlantic and the Pacific coasts. Thirty species and subspccics are recognized. Twenty-nine of these are assigned to the subgenus Procyon and one to the subgenus Euproc yon.

The revision is based mainly on a study of raccoon material in the collection of Biological Surveys, Fish and Wildlife Service, and in other collections in the United States National Museum. These and 358 specimens borrowed from other museums make a total of 1,337 examined. The assemblage included the types or topotypes of most of the known species and subspecies.

For the loan of specimens the writer is especially indebted to Dr. Thomas Barbour, Museum of Comparative Zoology, Cambridge, Mass. ; the late Dr. Joseph Grinnell, Museum of Vertebrate Zoology, Berkeley, Calif.; Dr. W. H. Osgood, Chicago Natural History Museum, Chicago, Ill.; Dr. H. E. Anthony, American Museum of Natural History, New York City; Dr. R. M. Anderson, National Museum of Canada, Ottawa, Canada; the late Oldfield Thomas of the British Museum (Natural History) ; Francis Kermode, Provincial Museum, Vancouver, British Columbia; Dr. L. R. Dice, Museum of Zoology, University of Michigan, Ann Arbor, Mich.; and the late D. R. Dickey, Pasadena, Calif. Grateful acknowledgment is also due to Percy Shufeldt, La Cueva, N. Vex., for the generous donation of specimens collected by him in Campeche, Mexico. Notes on his examination of specimens in the British Museum have been kindly furnished by Dr. Remington Kellogg, United States National Museum, Washington, D. C. Stanley P. Young, Fish and Wildlife Service, Washington, D. C., generously supplied the photograph for the frontispiece.

Dr. E. W. Nelson became keenly interested in the raccoons, as shown by his work on those inhabiting the Florida Keys (1930a).' During the same time and in the following year new subspecies were described jointly by Nelson and the writer in preparation for a revision of the group; but other projects claimed attention and our collaboration could not be carried beyond this preliminary stage