Police believe this woman maced and a attacked an L train rider following an argument. View Full Caption DCPI

WILLIAMSBURG — The MTA's "Courtesy Counts" campaign was lost on this straphanger.

A woman attacked a fellow rider aboard the L train, spraying him with Mace after the two argued over the man's coughing, according to the NYPD.

The suspect and the 45-year-old man were waiting at the First Avenue station just before 3:30 a.m. on May 23 when they got got into an argument after the man coughed, police said.

The train arrived and the man jumped into the last car as it traveled toward Brooklyn, police said. As the train coasted into the Bedford Avenue stop, the woman approached him and attacked him, spraying Mace at him, jumping on top of him and striking him, police said.

Emergency workers rushed to the Bedford L train stop and treated the victim for injuries to his left knee, the back of his neck and his eyes, according to police.

The woman, who was dressed in all black carrying an umbrella, fled the scene, police said. There were no arrests as of Monday morning, police said.

Anyone with information in regards to this incident can call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477).