ALASMODONTA. 
1. Calceolus, 
2. *Marginata, 
1. Acutissimus, 
2. Apiculatus, 
3. Carolinianus, 
4, Capax, 
5. Clava, 
6. Complanatus, 
Fs Cordatus, 
8. Decisus, 
9. Declivis, 
10. Delumbis, 
11. Donaciformis, 
12. Ligamentina, 
13. Lienosus, 
14, Metanever, 
15. Nodulatus, 
16. Obliquus, 
17. Pachostea, 
Say, 
UNI 
Lea, 
Say, 
Bosc, Fer. 
Green, 
Lam. Fer. ; 
Sol. Lea, Fer. 
Raf. 
Lea, 
Say, 
Con. 
Lea, 
Lam. Fer. 
Con. 
Raf. 
Raf. ; 
Raf. Fer. 
Unio calceolus, 
Alas. marginata, 
O. 
Conradicus, 
asper, 
obesus, 
Symphynota globosa, 
scalenius, 
modioliformis, 
purpureus, 
undatus, 
trigonus, 
var. Taitianus, 
geometricus, 
modioliformis, 
ellipsaria, 
Nashvillianus, 
retusus, (very old,) 
pustulatus, 
prasinus, 
Schoolcraftensis 
obovalis, 
ebenus, 
Cooperianus, 
Lea, 
Say, 
Lea, 
Lea, 
Lea, 
Lea, 
Raf. 
Say, 
Say, 
Barnes, 
a, 
. Lea, 
Lea, 
Lea, 
2 A specimen in the collection of the Academy of Natural 
Sciences, from Ohio, marked “truncata,” Say, led me to infer 
Say had described it as a distinct species; but I was mis- 
en. 



