1 EXHIBIT 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our report included in this Form 10-K into the Company's previously filed Registration Statements on Form S-8 (SEC File No. 33-48270 and SEC File No. 33-33190). /s/ ARTHUR ANDERSEN LLP San Antonio, Texas March 24, 1998