IV INTRODUCTORY NOTICE. 



proposed to myself at the commencement. That many errors may have escaped 

 me, I think extremely probable ; such are, in fact, insepai-able from the nature 

 of the task. I can only hope that what has been done may be received in a 

 proper spirit, not only by those who appear to think that " nobis " and " mihi " 

 are the chief end and aim of natural science, but by the genuine student of 

 nature. 



The system of Cuvier has been adopted as the basis of classification, with 

 such modifications as appeared to me necessary to render it more natural, and 

 to correspond with my general plan. For the chief of these modifications, I 

 am indebted to the excellent Manual of Sander Rang. My i-esearches among 

 the many volumes on this subject, both American and foreign, have been 

 numerous ; but it is chiefly to the labors of my own countrymen that I have 

 been indebted for the following pages, 



Syosset, Queens County. 

 February 1, 1844. 



