Pomacea bridgesii “mystery snail”- these snails are not plant eaters but REQUIRE permits to sell across state lines. Make sure your seller has these permits PLEASE! It is ONLY legal to sell the snails, it is ALWAYS illegal to sell the eggs. Edit: No longer illegal to ship without permits.
Malaysian Trumpet Snails- no restrictions
Common ramshorns- no legal restrictions
Common pond/tadpole snails- no legal restrictions
Anatome Helena “assassin snails”- no current restrictions
Nerites- no current restrictions, although there are some state by state broad-based import laws
Japanese Trapdoors- not restricted
Asolene spixi “zebra apple”- these are banned from transport. These snails lay their eggs in clutches UNDER the water line, can interbreed with Columbian ramshorns and often eat plants as juveniles, even when not a mixed species.
Marisa Cornuarietis “Columbian ramshorn”- Banned from transport.
Pomacea canaliculata “channeled apple snail”- banned from transport
Pomacea haustrum “triton apple snail”- banned from transport
Pomacea paludosa “Florida apple snail, flapple”- banned from transport
However, Puerto Rico is not actually a state so not sure if this applies or not.