1 56 APPENDIX. 



30. Unio ventricosus, Barnes. Upper Mississippi, from Prairie du 

 Chien to Lake Pepin and Shell Lake. The varieties of this, and the 

 preceding pass insensibly into each other. Those from Shell Lake are 

 of extraordinary s'ze. 



31. Unio alatfs, Say. Symphynota alata, Lea. Upper Miss : s* 

 sippi, and Shell Lake. Found also in Lake Champlain, by the late Mr. 

 Barnes. 



32. Unio gracilis, Barnes. Symphynota gracilis, Lea. Upper 

 Mississippi, and Shell Lake. The specimens brought by Mr. School- 

 craft are larger and more beautiful than I have seen from any other 

 locality. 



