Santa Barbara-based Circon Corp. said it rejected U.S. Surgical Corp.'s fourth bid, calling the $16.50-a-share, or $235-million, offer for the maker of surgical devices too low. U.S. Surgical first offered to buy Circon in August 1996 for $18 a share, a bid that was lowered to $17 and then $16.33. Circon rejected each offer. U.S. Surgical filed a lawsuit against Circon on Aug. 13 to let shareholders vote on the offer. Circon's board asked shareholders not to respond to U.S. Surgical's Aug. 5 tender offer, citing financial advisor Bear, Stearns & Co.'s opinion that the offer was "inadequate." Norwalk, Conn.-based U.S. Surgical owns about 1.96 million shares of Circon, or about 14.8% of the company. Shares of Circon rose 19 cents to close at $15.75 on Nasdaq, while U.S. Surgical shares rose 25 cents to close at $32.75 on the NYSE.