I like the weird poetry of mollusc names.

Currently this list is all American freshwater species, as the eastern rivers had a really tremendous quantity and diversity of them. There used to be a huge fishery for them, as recently as the 1930s, for the manufacture of buttons. You know how nearly all of our shirt buttons are white and slightly pearly? That's plastic imitating the original look.

As you can guess from the past tense I used, there's been a sad story of overexploitation, water pollution, hydroelectric schemes destroying entire river systems, and introduced Zebra Mussels & Asian Clams. A distressingly large number of species are extinct or critically endangered, sometimes entire genera-worth.

Lots more detail on history, natural history, regional species, etc.: