80 AMERICAN JOURNAL 



valuable contributions to American Conchology, and include 

 tbe Author's papers in this department of Science to eleven 

 different works, with dates of publication ranging from 1714 

 to 1840, 



Besides nimierous genera and species of marine and of fossil 

 moUusca, nearly two hundred new species of American land 

 and fresh water shells are described ; of which many have been 

 identified and adopted by the distinguished naturalists who 

 have studied his works, notwithstanding the difficulty with 

 his which inadequate descriptions and rude figures have sur- 

 rounded them. 



Unfortunately, Eafinesque's personal character together 

 with the very few and confusedly named specimens which he 

 distributed, have prevented these identifications from beiag so 

 numerous or so complete, as in the case of Linnasus, Lamarck 

 and others, whose descriptions are in many cases even less de- 

 finite, but who surrounded themselves with scientific friends, 

 and bequeathed to prosterity rich and authentic collections of 

 shells. 



A close study of Rafinesque's generic and specific descrip- 

 tions has convinced us that he was possessed of a genius for 

 the subject, very far in advance of the age in which he lived ; 

 and that under more favorable auspices, his works would have 

 been quoted long ago, as those of a worthy pioneer in Ameri- 

 can Conchology. 



In this edition of Rafinesque we have the original paging 

 of the various papers preserved in brackets, while the text is 

 an exact reprint, all the typographical and etymological errors 

 being retained, in preference to making alterations which in 

 some cases might not be acceptable to the student. 



The work has additional attractions in the very copious 

 index, occupying seven pages of double columns, small type, 

 with reference to every genus, sub-genus, species or variety 

 mentioned. 



A brief notice of some of the American genera and species 

 described by Rafinesque may not be considered unacceptable, 

 and we offer no apology for rehearsing a subject which has 

 puzzled older and abler Cohchologists, except that we believe 

 that each fresh mind brought to the investigation of difficult 

 questions, will evoke some new truths which his predecessors 

 have failed to perceive. We are besides, in many cases, merely 

 summing together and deducing results from tlie heretofore 

 undigested studies of a number of Naturalists. 



Of the genera of Ifeh'cidce, described by Rafinesque. the 

 following have been retained : — 



