Some of the Europe's best riders will be at Arlington Park for Million Day on Saturday. Most are known to American racegoers, but at least one will be new to these shores, as will the Brazilian rider of Gloria de Campeao. Here's a heads up on some of the lesser-known riders.\nChristophe Soumillon: "How many famous Belgians are there?" is a question often asked disparagingly of that little country. Well, for starters there are world-famous mystery writer Georges Simenon and saxophone inventor Adolphe Sax. More recently, there is Soumillon. Champion rider in France in 2003, 2005, and 2006, and never worse than third since 2002, Soumillon, 28, is first-string rider for the Aga Khan's powerful stable. He has won the Arc aboard Dalakhani and Zarkava; the King George VI and Queen Elizabeth Stakes on Hurricane Run; and the Breeders' Cup Turf on Shirocco. He also has won 13 classics - 11 in France and one each in Ireland and Italy. Oh, and eight Group 1's in Hong Kong. He will ride the Aga Khan's Alnadana in the Beverly D.\nChristophe Lemaire: The 30-year-old Frenchman has become one of the world's more prominent big-race riders in recent years, with 17 Group 1 tallies in France, five in England, three in Japan, and one each in Dubai and Hong Kong. His front-running victory aboard the Japanese-trained Heart's Cry in the 2006 Dubai Sheeema Classic brought him international acclaim. Contract rider for the Niarchos family, he rode their Divine Proportions to four Group 1 triumphs, including the French 1000 Guineas and the French Oaks. Aboard Natagora, also owned by the Niarchos family, he won the Cheveley Park Stakes and the 1000 Guineas. This season, he is the rider of Stacelita, the undefeated four-length winner of the French Oaks who is being compared in some circles to Zarkava. His Million mount is Cima de Triomphe.\nDominique Boeuf: Born in the French training center of Maisons-Laffitte, Boeuf apprenticed under Patrick Biancone and was champion rider in France four times from 1991 to 2002, riding frequently as the first string for the Wildensteins. Groom Dancer, Sillery, Bright Sky, Epervier Bleu, Pistolet Bleu, Helissio, Aquarelliste, and Westerner are some of his 23 Group 1 winners. The 42-year-old veteran will be seeking his first American victory with Denomination in the Beverly D.\nAdam Kirby: The 20-year-old Englishman will be riding for the first time in America aboard Stotsfold in the Million, on whom he won La Coupe at Longchamp on June 18 as well as the Winter Hill Stakes last year and the Select Stakes in 2007, all three of those races 1 1/4-mile Group 3's. He rides first call for a very good teacher in Stotsfold's trainer, Walter Swinburn, who won the Epsom Derby three times and was the rider of All Along during her championship season of 1983. Kirby scored his most recent stakes victory aboard the Clive Cox-trained 2-year-old Xtension in the Group 2 Vintage Stakes at Goodwood on July 29.\nTiago Josue Pereira: He has ridden more than 1,750 winners in 15 years in his native Brazil, among them the Group 1 Grande Premio Sao Paulo. The 32-year-old will make his American debut in the Million aboard Gloria de Campeao, whom he rode for the first time May 17 when winning the Singapore Airlines International Cup. Pereira was picked for that assignment by Gloria de Campeao's Brazilian-based Swedish owner Stefan Friborg, who races under the nom de course Estrela Energia Stables.