After two days of run-of-the-mill registration, Memorial Hall officials are prepared to confront somewhere between 500 and 1500 upperclassmen, Summer School students, and graduates as the first batch of the still-unregistered 3000 members of the University arrive today.

With only 920 names officially recorded on the cards in the manila envelopes, the bulk of what is undoubtedly the largest summer enrollment in Harvard's 300-odd years of history will enter Memorial Hall today and Monday.

Yesterday's meager registration of 213 Summer School and graduate students was called but the clam before the storm by Stanley K. Leonard, Chief Registrar, who expects that today's and Monday's flood of students will keep Memorial Hall clerks and solicitors busy from 9 until one o'clock.

Because most of the last day's registration in former years has come between 10 and 12 o'clock in the morning, upperclassmen are advised by veterans of the gauntlet to register early to avoid crowds and speed up the process of getting through Memorial Hall.

Immediately following yesterday's registration and as the doors were closed behind the last school teacher and graduate student, the debris of the day's action was cleared away and the envelopes and blanks for the early-arrivals of this morning's onslaught were laid out.

Although upperclassmen are looking forward to the opportunity of helping baffied Summer School beauties solve the mysteries of a Harvard registration blank, Mem Hall registrars have little hope that this innovation will do more than slow down the flow of students between the tables.