NEW YORK, OCT. 17 -- An enraged woman grabbed an alleged subway molester by the collar, dragged him off the train and beat his head against a concrete platform, transit police said today.

"She wanted to send a message out to the types of people who engage in this horrendous activity that there are a lot of women who are not going to stand for it," said Al O'Leary, a transit police spokesman.

The 27-year-old woman, whose name was withheld, is about 5-feet-6 and average weight but described herself as "very large in spirit," O'Leary said.

The woman said she tried to move away when the man fondled her back, thighs and buttocks, O'Leary said, but other riders on the train at 8:40 a.m. Friday seemed to not understand the situation and complained that she was crowding them.

When the doors opened at Grand Central, she dragged the man off the train, punched him and beat his head against the concrete platform. As he was being beaten, the man apologized and then asked a conductor to call police, O'Leary said.

Robert Davidson, 31, was arrested on a charge of third-degree sexual abuse. He lodged a criminal complaint against the woman on a charge of harassment.