Yes/no ---
println(Serial.list());prints a list of all the serial ports that are "active" on your machine.
The Serial.list()[n] is one of the strings, where n=0 is the first, n=1 is the second...
Now in your new Serial call, you can either use the Serial.list()[n] with the correct n-value or use that exact string inside "-quotes.
There is no need to use println(Serial.list());, once you know the port code "/dev/ttyb1" (or whatever yours is) which probably is fixed for a given connection.
(edits to fix a stupid formating error triggered by the processing syntax)