Are people in Australia and Texas pulling my leg? I began to wonder when two versions of the same story arrived in my mail within a week of each other.

Here's the Aussie version, sent by folklorist David S. Hults of the Curtin University of Technology, Perth:"A young girl was in line behind an elderly woman at a supermarket checkout counter. The woman stared at the girl, and eventually said, `Please pardon my staring, but I can't believe it. You're the spitting image of my dead daughter.'

"The woman then asked, `I know this sounds strange, but when I leave the store, could you say goodbye to me, and call me Mom, as a reminder of my daughter?'

"The girl, slightly embarrassed, agreed. And as the woman departed, the girl waved and said, `Goodbye, Mom.'

"Then the checkout clerk told her that the total bill for her groceries was $67.45. The girl was stunned, since she was buying only a loaf of bread and some milk. `But your mother, who just left, said you would pay for her groceries too,' the clerk explained."

Readers might recognize this as the legend that I call "The Grocery Scam." But the Down Under version concludes differently than the versions I'd collected from the U.S. and Canada:

"The girl ran outside the supermarket to nab the phony mother and force her to explain and to pay for her own groceries. The girl caught up with the woman in the parking lot, just as she was getting into her car to drive off.

"The girl grabbed her leg and tried to pull her from the car. She pulled and she pulled and . . ."

At this point the listener to the story usually asks something like, "Good grief, what happened?" The reply: "Well, she was pulling her leg, just like I'm pulling yours."

Aha! This is a "catch tale" - a story that leads up to an absurd situation, which the listener is forced to ask about. The storyteller's reply makes a fool of the listener, and so he or she is "caught."

Another popular catch tale leads up to a man trying to steal a package that the storyteller says he just got at a butcher's counter. "What was inside the package?" the listener asks. "Baloney," the teller answers, "just like I'm feeding you."

The most famous catch tale of all was popular during the frontier era. The storyteller claims that he was backed into a corner by fierce attackers, perhaps a band of hostile Indians. "What happened?" breathless listeners ask. The storyteller wryly replies, "They killed me!"

Nobody believes catch tales, of course, so an urban legend modified in this way has the effect of a joke.

Just a few days later I got the same altered "Grocery Scam" story as told in Australia in a letter from Charles Wukasch, of Austin, Texas.

The only difference in the Texas story was that the supermarket clerk herself ran into the parking lot after the con artist. Here too the story concluded: "She was pulling her leg, just like I'm pulling yours."

Wukasch, who says he heard the story from his brother, knows another version of the scam legend as well. In this one, a soldier asks a high-ranking officer in a restaurant if he will wave back to him in order to impress the soldier's girlfriend.

After their meal, as the soldier and his girl leave the restaurant, the soldier waves, and the officer waves back.

What the officer doesn't know is that the soldier has told the cashier that the officer is paying for his and his girlfriend's meals as well as his own. The soldier explains that the officer will wave in order to identify himself.

Maybe this is the sort of trick that led the military to make the rule that all personnel must wear name tags.