141 



and thoroughly and at once. 



This " Contribution " seeks to do little more than to call attention to a 

 neglected branch of animal life which will yield the student a mass of 

 valuable data and prove a veritable mine of pleasure. In it there has 

 been given simply, without attempt to discuss any scientific question, a 

 list of the forms credited to the state. Very many of those mentioned 

 have been seen within the state or in colleetioDS containing authentic 

 specimens. Others are listed on the authority of undoubtedly correct wri- 

 ters. How much has been already accomplished and what yet remains 

 to do the lists themselves will indicate. 



The general plan of simply naming a single locality, at most two or 

 three, has been followed in order that a definite locality within the state 

 would fix the form as belonging to the Indiana fauna. Not a single form 

 has been admitted that has been recorded from neighboring states not- 

 withstanding that such a course would have been justifiable on the 

 ground that the artificial lines imposed by state boundaries are unknown 

 to mollusks, and species found in localities close to Indiana may reasona- 

 bly be expected within its limits. This course would have largely in- 

 creased our list, but it was preferred to make a record only of those shells 

 known in the state. The student may rest assured that every species 

 named herein has been found in Indiana and will be found again. 



An attempt at a bibliography has been made. But works or papers 

 dealing with our shells solely are very few in number. General works 

 there are, quite numerous too, from which help may be had. These two 

 classes of information are given below in separate lists. The paucity of 

 literature pertaining to this state will be evident at a glance. 



The Ohio river has been a prolific source of Unionidfe. From that 

 stream come most of the forms of wide geographic distribution ; indeed, 

 most of them were originally made known from that river. The Wabash 

 and the White rivers have contributed many forms but most of them are 

 common to the Ohio. It has been the rule to insert in this list of Indiana 

 shells all the species which were originally described from the Ohio 

 whether there is special record of their occurrence within the limits of 

 the state or not. 



In every portion of the commonwealth it is hoped that persons will be- 

 come interested in these animals sufficiently to collect locally and send to 

 eome central point what may be found, in order that a complete list, with 

 distribution, varietal characters, and other facts of a biologic nature may 



