Atmosphere: A corporate touch of class for the family, with beef and decor on a grandlose scale.

Price range: Dinners $7.95 to $9.95, with a $3.50 child's portion.

Hours: Mondays through Thursdays from 5 p.m. to 10:30 p.m.; Fridays and Saturdays from 5 p.m. to 11 p.m.; Sundays from noon to 9:30 p.m.

Special facilties: Accessible by wheelchair. Booster seats for small childnre. Large parking lot.

Reservations: A telephone check wouldn't hurt.

Credit cards: All major cards accepted.

For whatever it may portend socio-economically, culturally or just gastronomically, be advised that Phineas of suburbia has come to the city.

Yes, Phineas has bumped his corporate cousin, the old Hot Shoppes, from the site next to counsin Roy Rogers at the Marriott family compound on Wisconsin Avenue NW.

Until the other evening, in fact, our foursome had never visited a Phineas (there's one in Rockville and a Pineas II in Springfield). But as many a local family already knows, the theme at these places is prime ribs.

The decor is something else. Outside, where the car hops used to roam in the 1950s, there are now bluish spotlights, a cluster of lit-up baby Christmas trees along one side and rows of parking spaces.

Inside is a foyer, first in a wandering series of rooms, every inch of which has been done heavily in nouveau-antique. You name it, there's one hanging or stashed somewhere: Low-slung fat tiffany lamps, mirrows, ferns, mugs, platters, books, more baby Christmas trees, horse brasses, gilt-framed paintings of country scenes and all the other trappings of a regional garage sale.

It was a Wednesday's shortly before 8 P.m., and we were informed there might be a short wait. That was exact, for it was all of 2 1/2 minutes before we were led down a hall, to the right and into the middle of a clump of tables.

Our guide for this trip left a tiny card on the table, which had on it the time of our arrival (7:57), the number in our party, a printed "bon appetit" addressed to the name we'd borrowed this time out and a mention of what a pleasure it was to have us with them, signed "Phineas."

At each place setting was yet another card: "Phineas Bill of Fare." It does not take long to read. The headline is "Prime Ribs of Beef" and the question is pretty much how you want it: "Phineas cut . . . a generous portion," or "English cut . . . three side cut . . . slowly browned, yet as you like it."

Each of these is $7.95, including a tour of the salad bar, a variety of baked breads and a popover, "complimented by Phineas' secret au jus and whipped creme horseradish."

That, unless you prefer rib eye and tails or steamed rock lobster tails at $9.95, is it. Obvious query: Are these children's portions? Answer: Kids may order the English cut and get two instead of three slices for $3.50.

Sold, said our 9-year-old daughter, and rare it possible, please. Hmm, said her 11-year-old brother, adding that hunger dictated a three-slice portion of rare, please. My wife and I ordered the Phineas cut, also rare, and I side-ordered some roasted potatoes for 50 cents.

While the Phineas-pholk were rustling this up, we took shifts casing the salad bar, which drew an instant glowing review from our daughter. She memorized the offerings for her report back: Carrots, red cabbage, celery, green peppers, cherry tomatoes, mushrooms, all kinds of breads, croutons, cheeses, bacon bits and name-your-dressing. My wife has offered a tip for future salad-bar-flies: Hold out for the Caesar's salad at the end of the line, for it's extremely good.

For beverages, the children each worked on a two-tiered glass of Coke, my wife chose a glass of rose and I had a bottle of beer (the draught beer here is the light stuff, if that's your thing).

Eventually we could almost blot out the disconcerting canned music and the anecdotes of the people at the table next to us.

Then came the beef - stunning in its rarity and, as our son observed, the melt-in-your-mouth kind of meat. Every portion was sizable, particularly the "Phineas cut," which was a 6-inch-long rib with inch-thick meat. (Good treats for the hounds at home, too, so we had the bones bagged up).

The popovers were properly warm and a plateful of butter from the salad bar did them up right. But if that potato side-order was seriously obeyed, you'd best forgo any call for them; what appeared were five oven-burned marbles.

For dessert, the kids shared an order of chocolate cheesecake for $1, while the parents had coffee and a glance at the computer-printout of a bill that came to $35.86 plus tip.

So even though Phineas certainly challenges the modest budget, he does dish out a certifiably good meal, neatly programmed to please the hungry family.