But, in 1896 Outram Bangs published "A Review of the Weasels of Eastern North America" in which he correctly recognized eight kinds. Although some of these were treated by him as full species, whereas the material accumulated since 1896 has shown that subspecific status is in order, his names, still in use, were correctly applied in every instance, save probably one. This was his use of _Putorius richardsonii_ for the animal now known as _M. e. arctica_. Unlike the earlier, excellent treatment by Baird, this accurate one by Bangs was heeded and followed by subsequent writers. For example, Dr. C. Hart Merriam in the same year, 1896, accepted Bangs' conclusions except for correcting the application of the name _richardsonii_. The principal contributions of Merriam's paper "Synopsis of the Weasels of North America" were first, the wider geographic scope and second, the naming as new of several kinds outside the geographic area studied by Bangs. Otherwise the work was not up to Dr. Merriam's usual standard and the internal evidence of haste in its preparation and the superficial study of some of the material at his disposal explain why the weasels of North America since that time have been but little better understood than in 1896. Baird and Bangs, then, unquestionably did the best systematic work on the American weasels. In 1916 Dr. Joseph A. Allen published a valuable paper on the South American weasels. The material available to him was inadequate and prevented a thoroughly satisfactory treatment. There are too few specimens even today to permit of a thorough treatment of the South American weasels in the present paper; nevertheless the material today is more nearly adequate than it was in 1916 and it is hoped that the systematic arrangement is correspondingly improved. Chronological List (annotated) of Specific and Subspecific Names Applied to American Weasels At least eighty-seven specific and subspecific names have been proposed for American weasels. Of these sixty-nine are now regarded as valid designations of recognizable subspecies. The average is 1.2 names per subspecies. Some names in the following chronological list were a second time applied wholly or in part to some other kind of weasel. In general, mention of the second or any other later application is omitted from the following list but two usages of _agilis_ (1844 and 1853) and of _americana_ (1865) are recorded.