restore a table in a database

How do I restore just a table to a database? I was able to create a backup of the required table from a backup of the database as follows.
I don't know how to properly restore the backed up table "departments" to the original "sms" database.

create a new db
createdb -U postgres smstest

restore a backup of the db to the new db
psql -U postgres smstest < /tmp/postgresql-sms-11-24-2008_04-05-database

backup up the specific table from the restored db
pg_dump -U postgres -a -t departments smstest > /tmp/smsdepartments

The table backup is smsdepartments. How do I restore smsdepartments to the table called departments in the sms database?

Thanks

Marc