EXHIBIT 23.1
 
                   CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS
 
  As independent public accountants, we hereby consent to the incorporation by
reference of our report included in this Form 10-K, into the Company's
previously filed Registration Statements File Nos. 333-50729, 333-28683-99,
333-66622-99, 333-75059, 333-75057, 333-75055.
 
                                          Arthur Andersen LLP
 
Washington, DC
March 25, 1999