When in Rome, eating as the Romans isn't always the familiar experience Americans expect. In fact, eating almost anywhere in Italy can hold startling surprises for the unwary tourist. Midsummer visitors to Mantova may discover their ravioli filled with pumpkin instead of cheese, while in Rome at Christmas they are as likely to encounter eels in tomato sauce as spaghetti.

Asking for "Genoa" salami will get travelers a quizzical stare, as its closest approximation in Italy is called "Hungarian" salami (salame Ungherese). Nor will ordering antipasto guarantee, as in Italo-American restaurants, a plate of olives, peppers, anchovies and salami, served on lettuce with vinegar and oil. The Italian word is merely a cover-all for an endless variety of appetizers.

In truth, Italian cuisine, though enormously popular in the United States and most European countries, is often misrepresented abroad. Certainly, it is more imaginative and varied than what passes for Italian in most American eateries, which tend to serve dishes popularized in this country by turn-of-the-century Neopolitan and Sicilian immigrants. Not that their talent for cooking was limited.

The Neopolitans -- who introduced pizza to America -- billed Genovese ravioli, Milanese ossobuco, Venetian scampi and other Northern Italian dishes alongside their Southern specialties on early restaurant menus. Walk into any Italo-American diner today and on the table will be a tumbler bristling with those Turinese breadsticks called grissini. But, except in gourmet establishments, menus in this country are generally predictable.

Not so in Italy, where genuine food, and how to cook it, remains so important that Italian phone directories list a number up front, next to police information, that you can dial to get regional recipes. Many such specialties are served by local trattorias, but -- either due to unfamiliarity with Italian or for fear of ordering a dish they might not like -- travelers are inclined to fall back on familiar fare.

Here, to help in ordering more adventurously at restaurants in Italy, is a guide to authentic daily dishes and specialties worth investigating throughout the country's diverse regions.

*Abruzzi. L'Aquila, capital of Abruzzi, is a city of about 100,000 just an hour and a half by car or bus northeast of Rome. Set in the valley of the towering Gran Sasso, the highest of Italy's Appennini Mountains, it is off the beaten track of many tourists, but worth a visit not only for its scenic splendor but also for its famed spaghetti alla chitarra. This is named for the "guitar" with which it is made -- a rectangular wooden frame with steel strings stretched across it, against which the dough is cut. The well-kneaded dough contains a little olive oil, and the rich texture of this handmade spaghetti is unique.

Also in the area, try trote del sangro al forno: trout from the Sangro River, oven-baked with garlic, capers, parsley, moistened with olive oil and coated with breadcrumbs. The white, pear-shaped cheese called scamorza is another must, and the deep-flavored mountain ham, prosciutto aquilano, should be savored, along with the "sweet" and "crazy" liver sausages dubbed fegati dolci and fegati pazzi. Away from the mountains, along the Adriatic shore, Pescara and other port towns specialize in the fish chowder called scapece, for which fish is first fried, then pickled in white vinegar laced with the saffron introduced to Abruzzi by 16th-century Spanish invaders.

*Apulia. This stretch of Greek-influenced Italy spreads from San Severo to Taranto, and encompasses Barletta, Bari and Brindisi on the Adriatic coast. The figs of Bari are prized throughout Italy. Have fichi mandorlati, figs heated with almonds, fennel seeds and bay leaves. Poponi are the marvelously perfumed melons of the Brindisi region, which, along with Taranto, is also noted for olives. A puddica here is a bun stuffed with green and black olives and anchovies. Taranto's mussel soup, zuppa mitili, is also superb. The little ear-shaped pasta, orecchiette, called recchietelle in Apulia, are served with sauteed vegetables or fresh ricotta. Also search out some bocche di dama, "ladies' mouths" -- cream puffs with white frosting.

*Basilicata, Calabria and Campania. In Potenza, the best-known town of the Basilicata region, they like food hot and spiced with ginger, a remnant of Saracen rule. The chief specialty is lepre alla cacciatore, rabbit cooked in a hunter's sauce with ginger, tomatoes, rosemary, sage and garlic. The Calabrese boast eggplant dishes galore. Note melanzane alla finitese, eggplants breaded, with pepper and pecorino (sheep's milk cheese), then deep-fried; also melanzane all'agrodolce, sweet-and-sour eggplant, made with vinegar, chocolate, sugar, cinnamon, nutmeats, Marsala and raisins.

Naples in Campania is the birthplace of the ubiquitous pizza alla napoletana that Americans dote on, plus calzone and macaroni. Less familiar to most tourists, but justly famous throughout Italy, is mozzarella in carozza, a kind of french toast sandwich with a melted mozzarella cheese center. Americans love spumone, of course, usually misspelled "spumoni," but be sure to sample the other delicious Neopolitan ice creams, such as stracchini and matonelle.

*Emilia-Romagna and Lombardy. Milanese minestrone, breaded veal and even the Christmas cake called panettone are highly popular in the United States. But busecca, which to the Milanese is what onion soup is to Parisians, has not been exported. It is a delicious combination of minced veal or beef tripe cooked with onion, celery, carrots and sage, served on slices of thick, peppered bread with grated cheese.

A Ravenna specialty to delight in, along with the city's famed mosaics, is frittate dolci di pinoli -- sweet pine-nut fritters. Be on the lookout, too, for the region's vanilla-flavored casadello cake. Luciano Pavarotti's hometown, Modena, is also the home of zampone, a nationally popular sausage made of stuffed pig's feet.

*Tuscany, Umbria and Lazio. The frittata, a daily dish in most Italian homes, is largely unknown to Americans. It is most often an egg omelet, flecked with vegetables such as zucchini or carrots, but can also be a mashed potato cake, stuffed with melted cheese and prosciutto or mortadella (the original bologna). The Florentine frittata combines eggs with parmesan cheese and spinach. The Tuscans also boast stracotto, the Italian version of pot roast, and merluzzo, Italy's tasty cod fish, is often encountered in Tuscany simmered in wine.

Truffles, called tartufi, are Umbria's major product and can be sampled in pasta sauces or with meats, from Spoleto to Perugia. Scaloppine alla perugina combines thin, tiny veal scallops in butter with croutons, chopped chicken liver and ham. Delicious spit-roasted pigeon (palombacci allo spiedo) is another Umbrian delight. Perugia copies Rome for the herbed-roasted pork called porchetta, widely available at outdoor market stands.

As for the Eternal City itself, buy some suppli -- breaded croquettes of tomato-rice, cheese or potatoes -- an ancient "fast-food" staple. If you like pasta spicy, try it all'arrabbiata, garnished with hot peppers, tomatoes and pimientos. Stuffatino alla romana is a hearty beef stew cooked with onions, garlic, bacon and marjoram. Lumache, or snails, are a Roman specialty, too, simmered with tomatoes, garlic, anchovy, rosemary, parsley and mushrooms. Romans also love the fat, tasty eels they call capetoni, which are specially prepared at Christmastime.

*Liguria and Veneto. Focaccia, a flattened square of pizza dough, usually filled with onions or cheese, is a Ligurian specialty sold particularly near Genoa. Large vegetable croquettes, notably of squash, artichokes or black mushrooms, are rather confusingly dubbed polpettone, which is also the Italian word for meat loaf. Along with its myriad fish dishes, Venetian specialties worth investigating include frittura secca, which mixes boiled veal, chicken, salami, eggs, parsley, grated cheese and nutmeg into walnut-size balls fried in butter; or the area's polpette di carne, beef meat balls combined with chopped salami, egg, plus pieces of candied citron and pine nuts (pinoli), Malaga grapes and cognac. After frying in butter, they are dusted with, of all things, sugar.