64 NEW YORK STATE MUSEUM 



not identical, shows that nothing of importance has been pubhshed on 

 the animal during the present phase of the study of North A.merican 

 mammals, a period dating from 1889. The type locahty of each form 

 is given in parenthesis after the first reference. The accented syllable of 

 all technical names is marked with an acute accent; and the derivation.- 

 of each name is placed in parenthesis at the end of the diagnosis 

 (Lat. Latin, N. Lat,=New Latin, Gk. Greek). All measurements are. in 

 millimeters followed (in parenthesis) by an approximate equivalent in 

 inches and sixteenths. 



As in the List of the mammals of New York^ my aim is to present the 

 subject as it stands today rather than to attempt to reach final conclu- 

 sions. Numerous forms are therefore admitted the status of which is still 

 in question. Though this course has its disadvantages, it seems the one 

 least open to objection at the present time, when any revisionary work 

 would necessarily be imperfect. 



The use of keys in botany and zoology is now too well understood to 

 require any special explanation. It must be remarked, however, that no 

 keys can be made by which single spec imens of closely related sub- 

 species can be invariably named. Certain species even differ from each 

 other by characters that can not be set down in a single line of print. I 

 have endeavored to base keys and diagnoses on the most tangible 

 characters available; but where the way is hard for the specialist it 

 can not be made easy for the beginner. 



Individuals affected with albinism, melanism and other abnormalities 

 frequently occur in all species. Compared Avith the place they hold in 

 popular estimation their interest is slight. They should be carefully 

 guarded against as extremely liable to cause difficulty in identification. 

 Such individuals seem possessed of a peculiar faculty for bringing them- 

 selves to notice. 



