DEE AGE. 
In my previous volume, the ‘“‘Synopsis of the Mammals of North 
America and the Adjacent Seas,’’ the field covered was from the 
northern boundary of Mexico to and including the Arctic Ocean. 
The present work is supposed to contain all the Mammals of the ~ 
remaining portion of the North American continent and the con- 
tiguous seas, from the northern boundary of Mexico to the Province 
of Cauca, South America, including the coast islands, as well as those 
of the Bahamas and the West Indies whose fauna is not completely 
related to that of South America. In the general treatment of the 
named forms the method adopted in the previous work has been 
slightly elaborated, and brief statements of the habits of the animals 
contained in the various families, and sometimes in the genera, have 
been given, together with the English name for each species or race, 
and keys for genera, subgenera, species, and races whenever these 
were sufficiently numerous to make such analytical tables desirable. 
For a very large number of the species and races it is well understood 
that no English names exist, and these had to be manufactured for the 
occasion, and are practically of little assistance for the recognition 
of the different animals; but Latin names appear to be distasteful to 
a small number of the laity, and only those in the vernacular are 
satisfactory, and it is to aid these that this departure from the pre- 
vious plan has been made. Numerous named species of many genera 
‘of Mammals have so close a resemblance to each other, both in their 
outward covering and cranial characters, that often it is very difficult 
to distinguish one from the other, and for them Keys are probably 
less satisfactory as a means of determining the various forms than for 
any other class of animals; but it seems that there is a desire for such 
aids, which to many have become necessary, and therefore an effort 
has been made to meet this need, which it is hoped will serve the pur- 
pose intended. The illustrations throughout the volume comprise 
not only various representations of the cranium of some selected 
species of nearly every genus and subgenus, as in the ‘‘Synopsis,’”’ but 
in addition a figure is given of some species either of a family or 
genus, or possibly both, as the peculiarities of the animals seemed 
to require for a better comprehension of their appearance in life. To 
those unfamiliar with the diversified forms of the many mammals 
dwelling within the limits embraced in this volume, these figures 
may be of assistance, and enable them more easily to recognize the 
animals whose descriptions are given in the text. 
Vv 
