I. CYCLAS. CYCLE. 



So called from the more or less rounded circumfe- 

 rence of the whole family. 



1 . Cyclas rivicola. River Cycle. 



2. Cyclas cornea. Horny Cycle. 



3. Cyclas calyculata. Capped Cycle. 



4. Cyclas lacustris. Lake Cycle. 



5. Cyclas amnica. Rivulet Cycle. 



6. Cyclas appendiculata. Appendaged Cycle. 



7. Cyclas pusilla. Minute Cycle. 



II. ANODON. FRESH'WATER MUSSEL. 



So called from the want of teeth to unite the two 

 hinges. 



8. Anodon cygneus. Swan Fresh-water Mussel. 



III. UNTO. UNION. 



So named from being the shell in which the fresh- 

 water Pearls, or Unions, are formed. 



9. Unio margaritiferus. Fresh-water Pearl Mussel. 



