pg_dumpall: does not exist database

I was trying to dump all my databases:
su - postgres
/usr/local/bin/pg_dumpall > /Volumes/Space/postgresql_060425.dump

I get:
" does not exist  database "foodmartto database "foodmart
", exiting: pg_dump failed on database "foodmart

I guess I had a database called foodmart at one time. However, it
doesn't show up in the DB list:
postgres=# \l
           List of databases
      Name      |  Owner   | Encoding
---------------+----------+-----------
barry         | barry    | SQL_ASCII
      | kahn     | SQL_ASCII
.
.
.


There is that one nagging line though with no DB name:
      | kahn     | SQL_ASCII

How do I drop this no-name DB?

Thanks,
Ari