IV PREFACE. 



correct thera in ray quotations, but it soon became evident that 

 the better way would be to follow the original strictly. I have, 

 therefore, done so, in the majority of cases. Many of the cata- 

 logues published without descriptions, and several of the general 

 works not having been transcribed in my MSS., have been placed 

 directly in the hands of the printer to be quoted. In these cases 

 the original has been followed exactly. Generally it is easy to 

 correct a typographical error — thus when an author describes a 

 Melania altalis, it is evidently a mistake for altilis. And it is 

 often easy to correct such errors as Helix immitissima, which my 

 knowledge of the names of our Helices, would enable me to change 

 to minutissima. But when I find a quotation of Helix materna, 

 even my special knowledge does not enable me to decide whether 

 the author refers to Helix fraterna or Helix interna. In genera 

 which I have not personally studied I should have no clue of this 

 kind to guide me. It has seemed best, therefore, to adopt the 

 plan of giving a faithful reprint of the original. Any corrections 

 of typography which my friends may make, should be confined, 

 therefore, to my own errors, omitting those repeated from the 

 original work. 



The geographical limits to which I have confined my work are 

 the whole continent of North America, including Greenland and 

 the Arctic regions on the north, and including on the south the 

 Mexican States of Chiapas and Tabasco. Thus the West Indies 

 are not included, nor should one expect to find as perfect a quota- 

 tion of the species of South Western Mexico as of any portion of 

 the United States. My limits are such as to embrace the fauna 

 of North America, but not that of Panama or the West Indies. 



All the quotations are given from personal examination of the 

 works quoted. The proof has generally been corrected from the 

 original work, thus avoiding many errors committed in transcribing. 

 As it cannot be hoped that no mistakes have escaped my scrutiny, 

 I particularly desire any person to call my attention to any that 

 may be noticed. 



W. G. BINNEY. 



Buklixctox, N. J., March, 1863. 



