The 55 students who appeared at the Plympton St. scooter lot yesterday evening to snatch up one of the abandoned vehicles on sale by the HCUA were in for a surprise. Instead of a honey-mouthed auctioneer, they met a taciturn University cop, slowly shaking his head.

At 11:45 a.m. that morning, the University had called the whole thing off.

As reason for the last-minute action, Dean Watson said last night that he and Dean Monro decided they wanted "no kind gathering at all." "We just didn't want it today," he explained, and refused to comment further. Wednesday night, undergraduates poured onto the Cambridge streets in the second student riot of the Spring.

The cancellation marks the first time the University has thus stepped in to call off an undergraduate gathering, according to Watson. He could recall no other instance of last-minute interference similar to yesterday's action.

Marc A. Slotnick '64, former HCUA member and organiser of the sale, termed the Dean's decision an "unnecessary inconvenience." "I don't agree that a gathering would have caused any harm," he said, "especially in light of the cold, rainy weather and the fact that the sale was set for 6:30 p.m., a time when many students are eating dinner.

"As it is," Slotnick went on, "a large mumber of people have been inconvenienced. It only hurts the image of the HCUA."

The only explanation Watson would give Slotnick for the cancellation, Slotnick reported, was that the deans wanted "to avoid taking any chances."

Barring further University interference, Slotnick announced, the auction, the proceeds from which will go to the Kennedy Library, will be rescheduled for Monday at 6:30 p.m.