When the newly elected congressman from Florida arrived here the other day to give Capitol Hill a look, he caused a bit of a bureaucratic stir.

He introduced himself all around as Connie Mack, from the 13th District. But like his famous grandfather, who managed the Philadelphia Athletics baseball team way back when, C.M.'s full handle is Cornelius McGillicuddy.

The boys in the office of the Sergeant-at-Arms had to list the new man on the official House of Representatives roll, and they didn't know what to do at first. Should the list C.M. in his abbreviated form, or in all the multisyllabic glory his grandfather made famous?

"Precedent!," someone cried. "Let's check and see what we've done in similar situations in the past."

It turned out that the record of the current Congress is neither fish nor fowl.

Fortney H. Stark Jr. and Paul N. McCloskey Jr. of California are both listed on the official roll as "Pete." Corinne C. Boggs of Louisiana is listed as "Lindy." Bill Green and Ted Weiss of New York didn't bother with any Williams or Theodores.

Equally informal were Reps. Pickle and de la Garza of Texas. You won't find Jake or Kika on their birth certificates -- but that's what you'll find on the House roll. Even out Very Own Local, Stanford Parris of Northern Virginia, is officially "Stan."

However, California Rep. Augustus F. Hawkins insists on the whole nine yards, even though he's Gus to just about everybody. Same with James C. Wright Jr. of Texas, better (and more frequently) known as Jim.

Who's "Michael Darr Barnes" of Maryland? Is that you, Mike? And get a load of the guy from the eighth district of Massachusetts: Thomas P. O'Neill Jr. Not even a pip of Tip.

Finally, somebody decided that they'd better carry C.M. in the way in which his home state governor certified him. And how was that? According to Lil Gans in the office of Gov. Bob Graham, "Connie Mack" is the new representative from the 13th District.

But calling out "Mr. Mack" during roll calls was only the half of it. How should C.M.'s paychecks read?

According to Charlie Mallon, the deputy Sergeant-at-Arms, checks require full names. So when it comes to sums, it's the long version.

What about Jimmy Carter's paychecks, you ask?Well, there weren't any, as such.

According to a Treasury Department spokesman, the former President was paid by electronic fund transfer to an account in the name of "Jimmy Carter," even though his legal name was and is James Earl Carter. The presidency, as always, has its perks.