The largest known populations, which are very small and isolated, are in the Meramec, Bourbeuse, and Gasconade Rivers of Missouri.
Royal Dutch Shell | Shell | Shell Oil Company | Richter magnitude scale | Secure Shell | shell | scale | Moment magnitude scale | Ghost in the Shell: Stand Alone Complex | Ghost in the Shell | Shell-Mex and BP | Shell Canada | Fujita scale | Shrapnel shell | Shell (projectile) | Scale model | gastropod shell | scale model | Scale insect | Rostral scale | National Shell Filling Factory, Chilwell | Unix shell | Shell Rock River | Shell Nigeria | Shell Australia | Scoville scale | Röchling Shell | Röchling shell | Nuclear shell model | Mercalli intensity scale |