NOTE. 



The following list of shells is made from my own personal collections, which probably 

 embraces the largest number and best series of American shells that has ever been offered to 

 the student for close scientific study. The large number of varieties offered add very much to 

 the value of the series, but it must be understood that some of them do not represent very great 

 differences from the preceding or the following variety or specie. The object being to show 

 their relations to one another by a closely graded series of intermediate forms. In some in- 

 stances I have not been able to do this, yet for the most part they are so arranged that their 

 relationship can be easily inferred. 



I have reduced many of the so-called species to varieties and am convinced that very many 

 more should be treated in the same manner. Some conchologists may differ from me in this 

 particular, but while I esteem their opinions highly I must be true to my own convictions and 

 trust to further study to prove the truth of my position. 



Next to the objects themselves I regard variation as the most instructive and important 

 part of the study of conchology, and when the student has become fairly familiar with it, he 

 will find it possesses a charm rarely found in other fields of investigation. The Land Shells are 

 largely arranged in groups, as suggested by the form and sculpturing of the shells, and I have 

 placed at the head of each group the species that seem to be the progenitor of those that follow. 



In this arrangement of the land shells, very little attention has been given to genera or 

 subgenera as I think it best to follow nature wherever she leads rather than to follow altogether 

 the vagaries of systematists and parlor students. This arrangement may also serve, not only to 

 attract attention to the relations existiug between the individuals of each group, but to the 

 necessity of some more natural classification of these interesting little animals. I am strongly 

 impressed that no system of classification can be devised that will be acceptable to a 

 majority of Naturalists until the laws of variation are more thoroughly understood, for they are 

 the key to the system. 



The nomenclature has been brought down to the latest date, f>nd every effort has been 

 made to make the series as scientifically correct as possible, and especial attention is invited to 

 the fact that all the shells listed on the following pages have been collected by myself person- 

 ally, and have not been picked up by travellers, or bought from irresponsible persons, so that 

 the localities given with each specie or variety can be relied upon as strictly correct. 



HRNRY HEMPHIUv. 



