Some of the names just can't help but jump out at you, even buried as they are among the 3,500 albums and artists listed in the Roundup record catalogue. Leadbelly, Woodie Guthrie, Louis Armstrong, Doc Watson.

But the Names are the exception here.

For the most part, the albums crowded into the 30 pages of the catalogue - 100 or more to a page - soring from the obscure nooks and crannies of American folk music.There are the works of Appalachian fiddlers and Cajun folksingers, New Orleans jazz trumpeters and string bands that once played the music of the southwest in small cafes along the Mexican border.

And the names of the recording companies are often less familiar than the musicians. Take the Spivey label, with its blue artists, or Flying Fish, or Kicking Mule, a label imprinted on 28 different albums, from a collection of Scott Joplin rags to Stefan Grossman's "Yazoo Basin Boogie."

"We're trying to work with artists and labels that have a lot going against them," said Kenneth Irwin, the man who, with two friends, founded the Rounder Record label then started up the catalogue (Irwin's enterprises tend to variations of "round" as a prefix - Rounder, Roundup, Roundhouse) in an effort to market his records and thos of other tiny companies.

In the eight years since, Irwin and perhaps a dozen people who worked with him have made the selling of non-commercial records a commercially viable venture. At the same time, the Rounder label has grown to include more than 125 folk and bluegrass records.

Ken Irwin and two friends started the mail order business out of the back of a van as they travelled from one small folk festival to another. When they got a chance, they would call back home to Cambridge, Mass., to see what orders had come in, Irwin said. "We had to stop in at radio stations and say 'Do you have any extra cartons?'" Then they would stuff the desired albums inside the castoff cardboard and send them off.

The price back then was $3.50 an album, and the 200 or so people who subscribed could choose from about 70 albums, mostly bluegrass - Irwin's first real passion - or the old-timey music born in the Apalachian hills.

Now, however, the whole business is a little more expensive, and a lot more eclectic. The albums that can be ordered from Roundup cost between $4 and $5.50 for the most part, though some of Woodie Guthrie albums on the Folkways label sell for $7 apiece.

Where once postcards were used as invoices, there are now form invoices to be filled out in triplicate. And what once was a one-page flyer is now a stapled 30-page catalogue with long typewritten lists broken up by illustrated panels from pulp westerns and 20-year-old comic books.

The selections include everything from Irish penny whistles to Yugoglavian gusle players to the music of "The Pygmies of the Ituri Forest." And aside from these more esoteric offerings, there is also a roster of artists and songs familiar to every protest movement of the century. There are labor organizing ballads and suffragette songs, new Chilean protest works and prison dirges from the American south.

The lists go on long enough to spend a lazy afternoon with, long enough to allow a person to drift off into whimsical reveries about what instruments the pygmies of the Ituri forest use to make their music.

And when you've finished daydreaming and decided that you do indeed want to order something, you can usually get your order filled and back to you in 10 days.

Even the better known of the albums in the catalogue - the records made by Pete Seeger or Gordon Bok, by Phil Ochs or Norman Blake - sell probably fewer than 25,000 copies. Ever. A Linda Ronstadt hit or a Shaun Cassidy album could outpace them in a week.

But volume sales are not so important to the people at Roundup's little warehouse in Sommerville, Mass. (There is no phone listed there. It's just a small old warehouse, with its mail coming in to a post office box.) "We keep the records in print, where a big firm with a lot of overhead might not," Irwin said.

"If you keep it in print, a record can sell pretty well over time."

A Roundup catalogue, as well as their bi-monthly capsule review of new recordings in "Record Roundup" can be obtained by writing the company at P.O. Box 474, Somerville, Mass. 02144.

Nor is Rounder the only small label/distributor to provide a catalogue with a potpourri of offerings. Locally, Adelphi Records, at 7054 Carroll Avenue in Adelphi, Md., also had a catalogue including other labels. And Sabin's, the jazz record center at 3212 Pennsylvania Ave. SE, will be coming out with a catalogue late this month including 35 to 40 jazz labels. CAPTION: Picture, no caption, Copyright (c) R. Crumb. From Roundup Records Catalogue.