Exhibit 23.1





                    CONSENT OF INDEPENDENT ACCOUNTANTS



     As independent public accountants, we hereby consent to the
incorporation of our reports included in this Form 10-K, into the Company's
previously filed Registration Statements on Form S-8 (File Nos. 33-44363, 
33-55090, 333-29439 and 333-62681).



                                        /s/ Arthur Andersen LLP
                                        -----------------------------
                                        ARTHUR ANDERSEN LLP



Washington, D.C.
March 30, 1999