An 18-year-old Lanham woman was sexually assaulted and robbed aboard a Metrorail car Monday evening by a man who found her alone, reading a Bible on the car, and terrorized her for a quarter-of-an-hour as the train rode from Prince George's County into the District, police reported.

The woman said her ordeal began about 7:30 p.m. after she had boarded the empty second car of an Orange Line train at the New Carrollton station at the end of the line in Prince George's County. The man got on moments before the door closed, she said.

The woman told police the man asked her for the name of the next subway stop and she told him it was the Landover station. After the train stopped at Landover and the Cheverly stat;on, the man approached, placed his hand inside his shirt and said he had a gun, she said.

"I was on my way to my boyfriend's in Rosslyn, reading my New Testament," the woman said. "The man asked me for my money.

The man took $40 from her, she said, and she tried to talk him out of harming her.

"I offered him my Bible. First he said yes, he would take it. Then he switched. He got angry. He said, 'You really want to see Jesus. I'll kill you, you'll see Jesus real quick.'"

The man then took the woman to the back of the car and forced her to commit sodomy, telling her he would have raped her if there were enough time.

In the course of the assault, which continued through stops at the Deanwood and Minnesota Avenue stations, the woman was slapped in the face.

"I was very upset inside," the woman recalled yesterday. "I was very afraid. I prayed out loud. He said 'I just came from the penitentiary. You don't mean nothing to me.'"

When the train stopped at the Stadium-Armory station, the man forced the woman onto the platform, where she screamed for help, police said.

A female station attendant came to her aid. As the assailant released the woman and fled, the attendant pulled the woman back into the car and radioed for help.

The woman was taken to D.C. General Hospital, where she was treated and released.

The woman, interviewed by telephone yesterday, said she was willing to tell her story because she wanted to "let people know that Metro wasn't safe."

The assault was the first sexual crime reported to date on WashingtonS three-year-old subway system.

Officials said police officers were aboard the trains that left New Carrollton before and after the one on which the woman was attacked, but were not on that particular train.

Security for subway riders has been a major issue since Metro was planned in the late 1960s. Metro has its own 250-member police force and has spent millions of dollars for closed-circuit television cameras on station platforms and mezzanines.

There are no cameras in the cars, however, and, unlike New York City, Metro does not have a requirement that there be a police officer on every train. Usually one Metro police officer will patrol two or three stations plus the trains that run between them.

The size of the Metro police force has been a major budgetary issue with local governments over the last few years.