REDWOOD CITY, Calif. - A noted child psychiatrist pleaded not guilty yesterday to charges he molested seven boys in his care, and his lawyer said the accusers had mistaken routine physical examinations for sexual abuse.

William Ayres, 75, appeared briefly in San Mateo County Superior Court with his wife and lawyer at his side as a prosecutor added three additional counts involving two more alleged victims to the indictment.

Dozens of Ayres' former patients, dating to the late 1960s, have come forward to accuse him of abusing them, but in many cases the allegations fall outside the statute of limitations.

Ayres faces 21 counts of lewd and lascivious behavior involving seven former patients. Five of the seven were between 9 and 12 when the abuse allegedly took place.

Ayres was elected president of the American Academy of Child and Adolescent Psychiatry, serving from 1993 to 1995, and received accolades from county officials for his "tireless effort to improve the lives of children."

Prosecutor Melissa McKowan would not discuss details involving the two new alleged victims. She told Ayres' lawyer she expected that two more boys soon would be added to the case.

McKowan said many more alleged victims, both within and outside the statute of limitations, were continuing to come forward. At last count, she said there were nearly 40.

Prosecutors say Ayres would get the boys alone in his examination room under the pretense of giving them a physical.

Defense lawyer Doron Weinberg said no abuse took place. "Dr. Ayres did not molest them," he said outside court. "They were mistaken."