to their proper place among the synonyms. The present time can 

 not be supposed as opportune for a final and satisfactory revision of 

 the various groups contained in this Synopsis. That must be the 

 work of some future Mammalogist who can bring to the task not only 

 a thoroughly unprejudiced mind, but who may have acquired a more 

 intimate acquaintance with the quadrupeds of those sections of our 

 country, as yet little known, and whose knowledge of geographical 

 distribution of mammals, the extent of the individual variation of 

 crania, the relationships that apparently different forms have for each 

 other, and the changes in color assumed by the pelage throughout 

 the year, and in some cases adopted by the sexes, has been gained 

 from extensive series of specimens, much greater and more complete 

 than those possessed by any naturalist at the present day. Then 

 only can a list of our mammals be made that will be comparatively 

 permanent and satisfactory. This Synopsis, therefore, may only be 

 regarded as a starting point upon which such a final list may be 

 founded, and does not purport to indicate how many Species of mam- 

 mals there are in North America, but merely to show how many 

 forms are given some kind of a distinctive rank at the present time 

 that are more or less recognizable, but whose ultimate scientific 

 standing is subject to future revision and correction, and in this light 

 the author trusts the book may be useful to his fellow workers. 



An earnest effort has been made to include all described forms 

 that are entitled to a place in this Synopsis, yet in spite of the utmost 

 care some may have been omitted, but it is hoped they are few in 

 number. In the descriptions of the various species and subspecies, 

 it has been attempted to emphasize the salient characters of each 

 form, when existing, and to contrast them with those of the nearest 

 ally, not always, it must be acknowledged, with signal success, as in 

 not a few instances the characters (?) have been so insignificant and 

 obscure as not to permit of an intelligent comparison, but the best 

 has been done that the circumstances would allow. In certain cases 

 where two or more described forms closely resembled each other, the 

 author's name has been quoted and his description given, so that, 

 whatever " claims " for distinctive rank may be shown to exist, they 

 could be presented in the most favorable light. In some instances 

 measurements have been given of the average of a number of 

 examples; but the majority are those of some selected specimen. As 

 there is, of course, considerable variation among individuals of a 

 species, allowance for this must be made, if the size of an example in 

 hand does not entirely agree with the figures in the description of 

 that species. Unless otherwise stated all measurements are given in 

 millimetres. 



