Resolution:
Here is the procedure for the temporary deletion of Enterprise Roles for roles which no users have been assigned.

1.    This procedure works for Roles for which no users have been assigned.
2.    Make note of the ENTERPRISE ID of the Enterprise in Question.
a.    SELECT ENTERPTISEID FROM ENTERPRISE WHERE NAME=’your_enterprise_name’;
3.    Create a Bogus Enterprise with a Unique ID Number in the ENTERPRISE Table.  Make sure the ID number is smaller than the highest ID                 number in the ENTERPRISE Table.
a.    SELECT MAX(ID) FROM ENTERPRISE;
b.    INSERT INTO ENTERPRISE (ID, NAME, INTERNALNAME) VALUES (1234,’BOGUS2’,’BOGUS2’).
4.    Change the ENTERPRISEID of the role in question in the ROLE Table to agree with your new Enterprise ID.
5.    Check your work by logging in as admin to your enterprise and creating a new user.  You will see that the role in question is no longer                 available for assignment to new users.
6.    If you want to reinstate the roles, simply change the ENTERPRISEID of the role in question in the ROLE Table.  Change it back to the                          enterprise you want the role active in.