PREFACE. 
XXIX 
The following table will serve to indicate the additions in the list to the known species of 
North American mammals, as compared with the latest general work on the subject: 
Species described here, as new, for the first time. 35 
Species described in 1855, from the same collection..... 1!7 
Total of new species in the Smithsonian collection not mentioned by Audubon and Bachman 52 
Recognized species previously described, not mentioned by Audubon and Bachman. 18 
Total of North American species additional to the list of Audubon and Bachman... TO 
The entire number of species mentioned by Audubon and Bachman in the Quadrupeds of 
North America, exclusive of varieties, is 19T, of which afiout 160 were figured, the remainder 
consisting either of species previously described by the authors, but not procurable for purposes 
of illustration, or else copied from others, to render their work complete. 
The total number of species of North American mammals represented in the Smithsonian 
collection is very nearly 220. 
Washington, D. C., July 20, 1857. 
