To George B, Emerson, Esq., 



Chairman of the Zoological Commission '. 



Sir, 

 In the execution of the trust committed to my hands, that of making 

 known the Quadrupeds of the State, I have been governed by the 

 principle, that general utility was the object to be aimed at. In view 

 of the present state of our knowledge, I concluded, not without much 

 hesitation, that this object would be best secured by a faithful and 

 accurate description of the animals within our borders. This con- 

 clusion was forced upon my mind, when I found it necessary to study 

 the characters of animals with a view to their recognition ; for I saw, 

 in the course of my investigations, that little had been done in the 

 application of distinctive characters, and that, therefore, in this par- 

 ticular part of science, there was a field which required cultivation. 

 Having adopted these views, it became necessary that I should in- 

 vestigate, examine, and describe for myself those animals in the 

 branch of Natural History which had been assigned me. Of the 

 execution of this task, all that I desire to say is, that it will be found 

 accurate and true to nature. I may not have been sufficiently minute 

 in the description of some of the most characteristic parts, as the teeth, 

 for example. Still, I believe that the most essential characters are 

 given. In drawing up generic and specific characters, I have studied 

 brevity as far as I deemed it useful. My general descriptions and 

 observations, I might have extended to a much greater length ; but, 

 in this particular, I have attempted to avoid extremes. Of the de- 

 scriptions, characters, observations, and dimensions, I remark, gen- 

 erally, that they are my own, and that they are given from actual in- 

 spection, and with the objects before me at the time they were penned ; 

 a few instances only have occurred in which I have not had the speci- 

 men before me from which I could draw up a description. In those 

 instances, I have, of course, relied upon the most approved authority. 

 As it regards the additions to our Fauna, I may remark, that I have 

 been able to add only two new species. Both of these belong to the 

 genus Arvicola, under which they will be found described. From 



